SEC Info℠  
    Home      Search      My Interests      Help      Sign In      Please Sign In

IAC Inc. – ‘10-Q’ for 3/31/23 – ‘EX-101.DEF’

On:  Tuesday, 5/9/23, at 4:30pm ET   ·   For:  3/31/23   ·   Accession #:  1800227-23-16   ·   File #:  1-39356

Previous ‘10-Q’:  ‘10-Q’ on 11/9/22 for 9/30/22   ·   Next:  ‘10-Q’ on 8/8/23 for 6/30/23   ·   Latest:  ‘10-Q’ on 5/7/24 for 3/31/24   ·   5 References:   

Find Words in Filings emoji
 		  in    Show  and   ↓Hints

  As Of               Filer                 Filing    For·On·As Docs:Size

 5/09/23  IAC Inc.                          10-Q        3/31/23   83:11M

Quarterly Report   —   Form 10-Q

Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML   2.49M 
 2: EX-10.1     Material Contract                                   HTML     30K 
 3: EX-10.2     Material Contract                                   HTML     50K 
 4: EX-31.1     Certification -- §302 - SOA'02                      HTML     28K 
 5: EX-31.2     Certification -- §302 - SOA'02                      HTML     28K 
 6: EX-31.3     Certification -- §302 - SOA'02                      HTML     29K 
 7: EX-32.1     Certification -- §906 - SOA'02                      HTML     25K 
 8: EX-32.2     Certification -- §906 - SOA'02                      HTML     25K 
 9: EX-32.3     Certification -- §906 - SOA'02                      HTML     25K 
15: R1          Cover Page                                          HTML     80K 
16: R2          Consolidated Balance Sheet                          HTML    144K 
17: R3          Consolidated Balance Sheet (Parenthetical)          HTML     37K 
18: R4          Consolidated Statement of Operations                HTML    119K 
19: R5          Consolidated Statement of Comprehensive Operations  HTML     71K 
20: R6          Consolidated Statement of Shareholders' Equity      HTML    101K 
21: R7          Consolidated Statement of Shareholders' Equity      HTML     29K 
                (Parenthetical)                                                  
22: R8          Consolidated Statement of Cash Flows                HTML    134K 
23: R9          The Company and Summary of Significant Accounting   HTML     67K 
                Policies                                                         
24: R10         Dotdash Meredith Restructuring Charges              HTML     72K 
                Transaction-Related Expenses                                     
25: R11         Financial Instruments and Fair Value Measurements   HTML    154K 
26: R12         Long-Term Debt                                      HTML     50K 
27: R13         Accumulated Other Comprehensive (Loss) Income       HTML     49K 
28: R14         Segment Information                                 HTML    298K 
29: R15         Pension and Postretirement Benefit Plans            HTML     56K 
30: R16         Income Taxes                                        HTML     35K 
31: R17         Earnings (Loss) Per Share                           HTML     64K 
32: R18         Financial Statement Details                         HTML     68K 
33: R19         Contingencies                                       HTML     30K 
34: R20         Related Party Transactions                          HTML     32K 
35: R21         Subsequent Event                                    HTML     27K 
36: R22         The Company and Summary of Significant Accounting   HTML     82K 
                Policies (Policies)                                              
37: R23         The Company and Summary of Significant Accounting   HTML     41K 
                Policies (Tables)                                                
38: R24         Dotdash Meredith Restructuring Charges              HTML     72K 
                Transaction-Related Expenses (Tables)                            
39: R25         Financial Instruments and Fair Value Measurements   HTML    156K 
                (Tables)                                                         
40: R26         Long-Term Debt (Tables)                             HTML     44K 
41: R27         Accumulated Other Comprehensive (Loss) Income       HTML     48K 
                (Tables)                                                         
42: R28         Segment Information (Tables)                        HTML    301K 
43: R29         Pension and Postretirement Benefit Plans (Tables)   HTML     55K 
44: R30         Earnings (Loss) Per Share (Tables)                  HTML     61K 
45: R31         Financial Statement Details (Tables)                HTML     86K 
46: R32         THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING   HTML     72K 
                POLICIES - Narrative (Details)                                   
47: R33         THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING   HTML     35K 
                POLICIES - Capitalized Contract Costs (Details)                  
48: R34         DOTDASH MEREDITH RESTRUCTURING CHARGES              HTML     31K 
                TRANSACTION-RELATED EXPENSES - Narrative (Details)               
49: R35         Dotdash Meredith Restructuring Charges              HTML     56K 
                Transaction-Related Expenses (Details)                           
50: R36         Dotdash Meredith Restructuring Charges              HTML     34K 
                Transaction-Related Expenses - Allocation of                     
                Restructuring Costs (Details)                                    
51: R37         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     31K 
                - Fair Value of Marketable Securities (Details)                  
52: R38         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     86K 
                - Narrative (Details)                                            
53: R39         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     37K 
                - Current Available-for-Sale Marketable Securities               
                (Details)                                                        
54: R40         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     26K 
                - Investments in MGM Resorts International                       
                (Details)                                                        
55: R41         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     30K 
                - Long-term Investments (Details)                                
56: R42         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     38K 
                - Realized and Unrealized Gains and Losses                       
                (Details)                                                        
57: R43         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     73K 
                - Assets and Liabilities Measured at Fair Value on               
                a Recurring Basis (Details)                                      
58: R44         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     39K 
                - Changes in Level 3 Assets and Liabilities                      
                Measured at Fair Value on a Recurring Basis                      
                (Details)                                                        
59: R45         FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS   HTML     36K 
                - Carrying Value and Fair Value of Financial                     
                Instruments (Details)                                            
60: R46         LONG-TERM DEBT - Summary (Details)                  HTML     53K 
61: R47         LONG-TERM DEBT - Narrative (Details)                HTML    118K 
62: R48         Accumulated Other Comprehensive (Loss) Income       HTML     77K 
                (Details)                                                        
63: R49         SEGMENT INFORMATION - Revenue by Reportable         HTML     59K 
                Segment (Details)                                                
64: R50         SEGMENT INFORMATION - Revenue Disaggregated by      HTML    108K 
                Service (Details)                                                
65: R51         SEGMENT INFORMATION - Revenue and Long-Lived        HTML     41K 
                Assets (Details)                                                 
66: R52         SEGMENT INFORMATION - Operating (Loss) Income and   HTML     69K 
                Adjusted EBITDA (Details)                                        
67: R53         SEGMENT INFORMATION - Reconciliation of Adjusted    HTML    129K 
                EBITDA to Operating Income (Details)                             
68: R54         PENSION AND POSTRETIREMENT BENEFIT PLANS -          HTML     50K 
                Components of Net Periodic Benefit Costs (Details)               
69: R55         PENSION AND POSTRETIREMENT BENEFIT PLANS -          HTML     32K 
                Narrative (Details)                                              
70: R56         PENSION AND POSTRETIREMENT BENEFIT PLANS -          HTML     29K 
                Expected Return on Plan Assets (Details)                         
71: R57         INCOME TAXES - Narrative (Details)                  HTML     51K 
72: R58         Earnings (LOSS) PER SHARE - Summary (Details)       HTML     95K 
73: R59         FINANCIAL STATEMENT DETAILS - Cash, Cash            HTML     35K 
                Equivalents, and Restricted Cash (Details)                       
74: R60         FINANCIAL STATEMENT DETAILS - Allowance for Credit  HTML     35K 
                Loss (Details)                                                   
75: R61         FINANCIAL STATEMENT DETAILS - Accumulated           HTML     30K 
                Amortization and Depreciation (Details)                          
76: R62         FINANCIAL STATEMENT DETAILS - Other (Expense)       HTML     39K 
                Income, Net (Details)                                            
77: R63         RELATED PARTY TRANSACTIONS - Narrative (Details)    HTML     61K 
78: R64         Subsequent Event (Details)                          HTML     44K 
81: XML         IDEA XML File -- Filing Summary                      XML    148K 
79: XML         XBRL Instance -- iaci-20230331_htm                   XML   3.15M 
80: EXCEL       IDEA Workbook of Financial Reports                  XLSX    167K 
11: EX-101.CAL  XBRL Calculations -- iaci-20230331_cal               XML    213K 
12: EX-101.DEF  XBRL Definitions -- iaci-20230331_def                XML    974K 
13: EX-101.LAB  XBRL Labels -- iaci-20230331_lab                     XML   1.84M 
14: EX-101.PRE  XBRL Presentations -- iaci-20230331_pre              XML   1.19M 
10: EX-101.SCH  XBRL Schema -- iaci-20230331                         XSD    177K 
82: JSON        XBRL Instance as JSON Data -- MetaLinks              522±   804K 
83: ZIP         XBRL Zipped Folder -- 0001800227-23-000016-xbrl      Zip    735K

‘EX-101.DEF’   —   XBRL Definitions — iaci-20230331_def

This Exhibit is an XBRL XML File.

                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with Wdesk from Workiva -->
<!-- Copyright 2023 Workiva -->
<!-- r:9b22e686-0338-4c23-abe2-b044d01035b8,g:512e35ff-dd13-49a3-aa3e-2389ca006b69 -->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
<link:roleRef roleURI="http://www.iac.com/role/CoverPage" xlink:type="simple" xlink:href="iaci-20230331.xsd#CoverPage"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CoverPage" xlink:type="extended" id="icd4c21251abe4272bf8afce2443ffabe_CoverPage">
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_4309ac00-7b64-407e-aee1-60c343603463" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentType"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentType_4309ac00-7b64-407e-aee1-60c343603463" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_a78a5cb7-b768-4e2c-97ee-689067a3b305" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentQuarterlyReport"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentQuarterlyReport_a78a5cb7-b768-4e2c-97ee-689067a3b305" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_7d6b9525-ac42-44d9-9719-0685df186543" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentPeriodEndDate"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentPeriodEndDate_7d6b9525-ac42-44d9-9719-0685df186543" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_4758561d-d2bb-4c6a-8a0d-327a72c7bf1a" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentTransitionReport"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentTransitionReport_4758561d-d2bb-4c6a-8a0d-327a72c7bf1a" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_566736b0-6b5a-4980-a619-55e57b1abcf9" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFileNumber"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityFileNumber_566736b0-6b5a-4980-a619-55e57b1abcf9" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_1cfbcbbe-3fa4-47cf-b9a6-1f5e5dc63b6a" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityRegistrantName"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityRegistrantName_1cfbcbbe-3fa4-47cf-b9a6-1f5e5dc63b6a" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_4ce0a563-b22e-40e4-928f-7237be79578e" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityIncorporationStateCountryCode"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityIncorporationStateCountryCode_4ce0a563-b22e-40e4-928f-7237be79578e" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_09033366-bf9d-4022-9173-69153c95b5a1" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityTaxIdentificationNumber"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityTaxIdentificationNumber_09033366-bf9d-4022-9173-69153c95b5a1" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_66b220fa-3af8-4bdf-a456-cde4117f91f7" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressAddressLine1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityAddressAddressLine1_66b220fa-3af8-4bdf-a456-cde4117f91f7" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_d750be4f-84a3-4f07-820f-93534e6eb08b" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressCityOrTown"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityAddressCityOrTown_d750be4f-84a3-4f07-820f-93534e6eb08b" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_4dd56a52-424f-4653-bbbd-3b0a12bb8bfb" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressStateOrProvince"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityAddressStateOrProvince_4dd56a52-424f-4653-bbbd-3b0a12bb8bfb" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_5faf2122-4801-4426-b500-a76bc347332c" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityAddressPostalZipCode"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityAddressPostalZipCode_5faf2122-4801-4426-b500-a76bc347332c" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_9298cc45-8248-4e8b-b62c-e6d2194290ed" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CityAreaCode"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_CityAreaCode_9298cc45-8248-4e8b-b62c-e6d2194290ed" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_78ead455-4fae-488e-9e2e-a76e6fb5907b" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LocalPhoneNumber"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_LocalPhoneNumber_78ead455-4fae-488e-9e2e-a76e6fb5907b" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_f0931800-a6b7-4b53-91a2-8bc7a38cd7b8" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_Security12bTitle"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_Security12bTitle_f0931800-a6b7-4b53-91a2-8bc7a38cd7b8" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_7207a9e3-d8e4-4ada-96fa-2d12bcf56fc3" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_TradingSymbol"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_TradingSymbol_7207a9e3-d8e4-4ada-96fa-2d12bcf56fc3" xlink:type="arc" order="15"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_a900f5ce-58d2-4b27-92dc-15048ddf579f" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_SecurityExchangeName"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_SecurityExchangeName_a900f5ce-58d2-4b27-92dc-15048ddf579f" xlink:type="arc" order="16"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_e668d45c-7553-411b-8e48-f610b6675f92" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCurrentReportingStatus"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityCurrentReportingStatus_e668d45c-7553-411b-8e48-f610b6675f92" xlink:type="arc" order="17"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_d7273109-1920-4b09-b19f-084ac27dbdc7" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityInteractiveDataCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityInteractiveDataCurrent_d7273109-1920-4b09-b19f-084ac27dbdc7" xlink:type="arc" order="18"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_ed89c749-69d0-42a6-9ef5-22218e7a618e" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityFilerCategory"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityFilerCategory_ed89c749-69d0-42a6-9ef5-22218e7a618e" xlink:type="arc" order="19"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_ecbace61-0c3e-44b5-aa10-a68b55fcaec2" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntitySmallBusiness"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntitySmallBusiness_ecbace61-0c3e-44b5-aa10-a68b55fcaec2" xlink:type="arc" order="20"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_82e4dcc2-d0d4-4bda-badf-9d92731b9eec" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityEmergingGrowthCompany"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityEmergingGrowthCompany_82e4dcc2-d0d4-4bda-badf-9d92731b9eec" xlink:type="arc" order="21"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_0aeab10f-72ed-4961-8349-6a4ec7e626cf" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityShellCompany"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityShellCompany_0aeab10f-72ed-4961-8349-6a4ec7e626cf" xlink:type="arc" order="22"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_642593a4-d0c5-4e05-9252-ce09b0dfe47d" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCommonStockSharesOutstanding"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_642593a4-d0c5-4e05-9252-ce09b0dfe47d" xlink:type="arc" order="23"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_21dfb347-184b-420e-a462-29db939cd1df" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCentralIndexKey"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_EntityCentralIndexKey_21dfb347-184b-420e-a462-29db939cd1df" xlink:type="arc" order="24"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_6450c3aa-9fc7-44da-a32d-371ceecf97db" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CurrentFiscalYearEndDate"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_CurrentFiscalYearEndDate_6450c3aa-9fc7-44da-a32d-371ceecf97db" xlink:type="arc" order="25"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_75d404c9-6888-48a6-a967-c51dcfb4acd1" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalYearFocus"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentFiscalYearFocus_75d404c9-6888-48a6-a967-c51dcfb4acd1" xlink:type="arc" order="26"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_c06f3e7c-f0df-45d6-8b01-2323a8df5c66" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentFiscalPeriodFocus"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentFiscalPeriodFocus_c06f3e7c-f0df-45d6-8b01-2323a8df5c66" xlink:type="arc" order="27"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_a2bc4bc8-0503-4271-b537-425cd6db34d8" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AmendmentFlag"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_AmendmentFlag_a2bc4bc8-0503-4271-b537-425cd6db34d8" xlink:type="arc" order="28"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_758d5145-3f00-4c9b-b437-8bf389b33025" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentInformationTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_eeec3246-4549-4c27-b1d4-c13761f0046b" xlink:to="loc_dei_DocumentInformationTable_758d5145-3f00-4c9b-b437-8bf389b33025" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_23229dcb-28c7-4d4d-ab68-526917845e28" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_758d5145-3f00-4c9b-b437-8bf389b33025" xlink:to="loc_us-gaap_StatementClassOfStockAxis_23229dcb-28c7-4d4d-ab68-526917845e28" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_23229dcb-28c7-4d4d-ab68-526917845e28_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_23229dcb-28c7-4d4d-ab68-526917845e28" xlink:to="loc_us-gaap_ClassOfStockDomain_23229dcb-28c7-4d4d-ab68-526917845e28_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_0f0d1d14-3fee-4647-a3d0-368285d611c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_23229dcb-28c7-4d4d-ab68-526917845e28" xlink:to="loc_us-gaap_ClassOfStockDomain_0f0d1d14-3fee-4647-a3d0-368285d611c0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_d67d5388-ade7-450d-91dc-bf7c21d998f2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_0f0d1d14-3fee-4647-a3d0-368285d611c0" xlink:to="loc_us-gaap_CommonClassAMember_d67d5388-ade7-450d-91dc-bf7c21d998f2" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_0c85b37b-3fe5-4cac-b438-2cf122b51400" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassBMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_0f0d1d14-3fee-4647-a3d0-368285d611c0" xlink:to="loc_us-gaap_CommonClassBMember_0c85b37b-3fe5-4cac-b438-2cf122b51400" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDBALANCESHEET" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDBALANCESHEET"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDBALANCESHEET" xlink:type="extended" id="i5e42cf95c36c4b85b25ecb6f0adf4ccb_CONSOLIDATEDBALANCESHEET">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_aa4be324-c2e4-444b-98a1-ed448e90e2b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_aa4be324-c2e4-444b-98a1-ed448e90e2b6" xlink:to="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_be90489c-4a84-4667-a736-e31b0ecf638a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_be90489c-4a84-4667-a736-e31b0ecf638a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermInvestments_d83acb50-6e3a-4046-9cbd-73eb058fbeb8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShortTermInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_ShortTermInvestments_d83acb50-6e3a-4046-9cbd-73eb058fbeb8" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_6f9997c4-6748-482a-801e-24ca4790d19b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsReceivableNetCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_6f9997c4-6748-482a-801e-24ca4790d19b" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_d0184f06-8d48-47f8-a964-dd14e69a292b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherAssetsCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_OtherAssetsCurrent_d0184f06-8d48-47f8-a964-dd14e69a292b" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_6170dcad-ed51-441b-8a9f-15734889ff98" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_AssetsCurrent_6170dcad-ed51-441b-8a9f-15734889ff98" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_361a920f-bd80-4f14-a98a-f6bcd08921ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_361a920f-bd80-4f14-a98a-f6bcd08921ae" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_ec993745-389b-45fe-bf00-581f5d24573b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_Goodwill_ec993745-389b-45fe-bf00-581f5d24573b" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_bd225786-8d6e-440d-b0a3-31a1da2d4306" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_bd225786-8d6e-440d-b0a3-31a1da2d4306" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_14285aa7-de61-4af7-8285-873809d09842" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_14285aa7-de61-4af7-8285-873809d09842" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_a0a94635-20de-4603-ae91-3e60d2e2e8a8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_LongTermInvestments_a0a94635-20de-4603-ae91-3e60d2e2e8a8" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_1c6fef98-ea08-4880-9074-876838d05c75" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherAssetsNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_1c6fef98-ea08-4880-9074-876838d05c75" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_7b72939c-82df-4afd-b791-9339ec94f627" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Assets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_3fda3dad-8214-4d10-9de5-7035461421d0" xlink:to="loc_us-gaap_Assets_7b72939c-82df-4afd-b791-9339ec94f627" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_aa4be324-c2e4-444b-98a1-ed448e90e2b6" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:to="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_6c2a9a53-cdb0-45cd-8c36-bb8f90c55b33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_LongTermDebtCurrent_6c2a9a53-cdb0-45cd-8c36-bb8f90c55b33" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableTradeCurrent_86756b94-9714-4546-81eb-0c7648eb3acb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsPayableTradeCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_AccountsPayableTradeCurrent_86756b94-9714-4546-81eb-0c7648eb3acb" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_55afe248-b1be-4e1d-8664-4ae782b6712b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_55afe248-b1be-4e1d-8664-4ae782b6712b" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_1efea86e-6c8f-4cf4-89f5-2e880bda84be" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccruedLiabilitiesCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_1efea86e-6c8f-4cf4-89f5-2e880bda84be" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_618c1482-1fe8-4540-82ee-7563b5b2f383" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_LiabilitiesCurrent_618c1482-1fe8-4540-82ee-7563b5b2f383" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_39ce8630-ee5e-456a-9518-5e2f3c2a1633" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_39ce8630-ee5e-456a-9518-5e2f3c2a1633" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_c5294a69-c37b-40b0-84c2-b49e436203ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_c5294a69-c37b-40b0-84c2-b49e436203ae" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_df8a9500-fbfe-4d6b-9b31-19f101373429" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_0a394d22-3e4f-45f2-b1d7-8142ec4f4f54" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_df8a9500-fbfe-4d6b-9b31-19f101373429" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_d8522a2f-3191-4827-a030-3032c0dba837" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_d8522a2f-3191-4827-a030-3032c0dba837" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_19fe21f5-5f8e-4008-a475-98dd48059c14" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommitmentsAndContingencies"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:to="loc_us-gaap_CommitmentsAndContingencies_19fe21f5-5f8e-4008-a475-98dd48059c14" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_17acc284-25ec-4997-bc6c-9577a4413d5c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_CommonStockValue_17acc284-25ec-4997-bc6c-9577a4413d5c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_900422a3-45be-441c-a381-262481b68b66" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_900422a3-45be-441c-a381-262481b68b66" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_8919bdfc-348d-414b-9054-7edacdd40131" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_8919bdfc-348d-414b-9054-7edacdd40131" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_78b7e0ac-4c47-41f4-a50a-dda6175db391" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_78b7e0ac-4c47-41f4-a50a-dda6175db391" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValue_37da5c1b-1d01-412b-bcc6-9fbe77d1eaec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_TreasuryStockValue_37da5c1b-1d01-412b-bcc6-9fbe77d1eaec" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_9b40a405-d3f2-4071-a917-235ccc25b4b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_StockholdersEquity_9b40a405-d3f2-4071-a917-235ccc25b4b8" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterest_ac7de231-18ce-4eb1-86fa-fca45d14a3c2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_MinorityInterest_ac7de231-18ce-4eb1-86fa-fca45d14a3c2" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d31d8d7-42af-4530-807f-43aa607c2bf8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_dd428f1e-7f2d-4088-a0d5-7373ad883c5d" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_7d31d8d7-42af-4530-807f-43aa607c2bf8" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_48d5e815-8fba-4bae-9c18-09996f58a5af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_e0d6a028-9ac0-44c8-bdcf-fea314aef129" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_48d5e815-8fba-4bae-9c18-09996f58a5af" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_f7bd28cb-8bae-470b-a17f-bbf21733b476" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_aa4be324-c2e4-444b-98a1-ed448e90e2b6" xlink:to="loc_us-gaap_StatementTable_f7bd28cb-8bae-470b-a17f-bbf21733b476" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_22b1f2af-2ae2-48cf-b981-534d70458051" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_f7bd28cb-8bae-470b-a17f-bbf21733b476" xlink:to="loc_us-gaap_StatementClassOfStockAxis_22b1f2af-2ae2-48cf-b981-534d70458051" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_22b1f2af-2ae2-48cf-b981-534d70458051_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_22b1f2af-2ae2-48cf-b981-534d70458051" xlink:to="loc_us-gaap_ClassOfStockDomain_22b1f2af-2ae2-48cf-b981-534d70458051_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_94fe6047-7e49-42ea-8c38-4d018f65995b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_22b1f2af-2ae2-48cf-b981-534d70458051" xlink:to="loc_us-gaap_ClassOfStockDomain_94fe6047-7e49-42ea-8c38-4d018f65995b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_6732486c-e2e7-4523-aa92-83d05fb9a02f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_94fe6047-7e49-42ea-8c38-4d018f65995b" xlink:to="loc_us-gaap_CommonClassAMember_6732486c-e2e7-4523-aa92-83d05fb9a02f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_e0aeb372-4cbf-4fee-a328-ce8e9ae7ac94" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassBMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_94fe6047-7e49-42ea-8c38-4d018f65995b" xlink:to="loc_us-gaap_CommonClassBMember_e0aeb372-4cbf-4fee-a328-ce8e9ae7ac94" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDBALANCESHEETParenthetical" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDBALANCESHEETParenthetical"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDBALANCESHEETParenthetical" xlink:type="extended" id="i639c0e527b6a4eadace21a742f5eec84_CONSOLIDATEDBALANCESHEETParenthetical">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_bcf88d06-8cd9-4aae-ac55-e38155ee77d1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_bcf88d06-8cd9-4aae-ac55-e38155ee77d1" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_b15451d7-9668-434c-9743-66478a5a15b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesAuthorized"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_b15451d7-9668-434c-9743-66478a5a15b8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_e673b486-b0ea-4de5-8022-bff676522010" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesIssued"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_CommonStockSharesIssued_e673b486-b0ea-4de5-8022-bff676522010" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_55b34246-718f-436e-ba98-1d6c315705ba" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_55b34246-718f-436e-ba98-1d6c315705ba" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockShares_4f8a37e4-c3a2-4173-b8e8-a29a8b9e58c4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockShares"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_TreasuryStockShares_4f8a37e4-c3a2-4173-b8e8-a29a8b9e58c4" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_af64b636-263d-4cfc-b04f-88f280f7bb33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_94d29b44-ae70-43ab-afc3-4999aa2a2c8c" xlink:to="loc_us-gaap_StatementTable_af64b636-263d-4cfc-b04f-88f280f7bb33" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_773d3bbf-b534-44c9-9be1-40ea1bc7f64f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_af64b636-263d-4cfc-b04f-88f280f7bb33" xlink:to="loc_us-gaap_StatementClassOfStockAxis_773d3bbf-b534-44c9-9be1-40ea1bc7f64f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_773d3bbf-b534-44c9-9be1-40ea1bc7f64f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_773d3bbf-b534-44c9-9be1-40ea1bc7f64f" xlink:to="loc_us-gaap_ClassOfStockDomain_773d3bbf-b534-44c9-9be1-40ea1bc7f64f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ab802614-5a7a-4a42-85b2-7536163ff750" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_773d3bbf-b534-44c9-9be1-40ea1bc7f64f" xlink:to="loc_us-gaap_ClassOfStockDomain_ab802614-5a7a-4a42-85b2-7536163ff750" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_db062d66-4512-4aef-b74b-ed53b83a1d69" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ab802614-5a7a-4a42-85b2-7536163ff750" xlink:to="loc_us-gaap_CommonClassAMember_db062d66-4512-4aef-b74b-ed53b83a1d69" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_a84d45e3-0029-43c0-97f7-031430b62e10" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassBMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ab802614-5a7a-4a42-85b2-7536163ff750" xlink:to="loc_us-gaap_CommonClassBMember_a84d45e3-0029-43c0-97f7-031430b62e10" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFOPERATIONS" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDSTATEMENTOFOPERATIONS"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFOPERATIONS" xlink:type="extended" id="ied25eaa99bf7417399a4327fe3638f46_CONSOLIDATEDSTATEMENTOFOPERATIONS">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d5286cc4-e8b5-4680-a165-d680fecf5a9b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_d5286cc4-e8b5-4680-a165-d680fecf5a9b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostsAndExpensesAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_34d957fd-118e-4157-91db-2dfad6889e72" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_34d957fd-118e-4157-91db-2dfad6889e72" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_5de0ca89-fd01-466e-b24d-49f559fe8339" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingAndMarketingExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_SellingAndMarketingExpense_5de0ca89-fd01-466e-b24d-49f559fe8339" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_27bbb251-77d5-4b1a-913e-08b47b32008d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_27bbb251-77d5-4b1a-913e-08b47b32008d" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_d3342b25-c965-4bca-a0ed-e0927fb08550" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_d3342b25-c965-4bca-a0ed-e0927fb08550" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationNonproduction_e2558378-c88d-4982-b026-7796cffd5a81" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepreciationNonproduction"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_DepreciationNonproduction_e2558378-c88d-4982-b026-7796cffd5a81" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_c040b313-3337-4f52-b3cb-ec7bec2e549e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_c040b313-3337-4f52-b3cb-ec7bec2e549e" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_be66153c-7bd0-406a-a78f-e30a0adb95d3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostsAndExpenses"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_39de2b5b-2bd0-4b0a-8bc8-8b49116cba08" xlink:to="loc_us-gaap_CostsAndExpenses_be66153c-7bd0-406a-a78f-e30a0adb95d3" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_3e3cdb4e-f589-471d-ac59-9f918d76c6b4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_OperatingIncomeLoss_3e3cdb4e-f589-471d-ac59-9f918d76c6b4" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_4b31897d-0bd7-4114-89f6-9a4fcc88abeb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_InterestExpense_4b31897d-0bd7-4114-89f6-9a4fcc88abeb" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_63166076-ef9c-4c0a-a39e-53d8b55d499e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_63166076-ef9c-4c0a-a39e-53d8b55d499e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_2f221d60-a984-4b55-8098-33ab55a24c4f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_2f221d60-a984-4b55-8098-33ab55a24c4f" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_faad9148-2ecc-40a4-9cee-5629b7b5082f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_faad9148-2ecc-40a4-9cee-5629b7b5082f" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_a02dcc25-8f61-4ed2-8f7c-2b6b78602937" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_a02dcc25-8f61-4ed2-8f7c-2b6b78602937" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_bf1d2f96-600b-49c4-a96f-8de680a5ce61" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_ProfitLoss_bf1d2f96-600b-49c4-a96f-8de680a5ce61" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_98a366b9-928f-4a46-91d2-2a38e4d24b33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_98a366b9-928f-4a46-91d2-2a38e4d24b33" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_3fd994ba-3ee0-4675-996c-f4cea3f035b9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_NetIncomeLoss_3fd994ba-3ee0-4675-996c-f4cea3f035b9" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EarningsPerShareBasicAndDilutedContinuingOperationsAbstract_0b8a0b68-e074-446a-b359-8ff88a87566b" xlink:href="iaci-20230331.xsd#iaci_EarningsPerShareBasicAndDilutedContinuingOperationsAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_iaci_EarningsPerShareBasicAndDilutedContinuingOperationsAbstract_0b8a0b68-e074-446a-b359-8ff88a87566b" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_a10cce8a-d181-4991-9704-0d072bfe67fc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_EarningsPerShareBasicAndDilutedContinuingOperationsAbstract_0b8a0b68-e074-446a-b359-8ff88a87566b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerBasicShare_a10cce8a-d181-4991-9704-0d072bfe67fc" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_5a8365c7-7037-4360-8e72-9fd7b5dd72fe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_EarningsPerShareBasicAndDilutedContinuingOperationsAbstract_0b8a0b68-e074-446a-b359-8ff88a87566b" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare_5a8365c7-7037-4360-8e72-9fd7b5dd72fe" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_NonCashCompensationExpenseByFunctionAbstract_4ebd2574-b084-4719-9f72-2cab06e166ae" xlink:href="iaci-20230331.xsd#iaci_NonCashCompensationExpenseByFunctionAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_iaci_NonCashCompensationExpenseByFunctionAbstract_4ebd2574-b084-4719-9f72-2cab06e166ae" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_5e033156-6005-4431-a0f2-badf9d03ee6f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_NonCashCompensationExpenseByFunctionAbstract_4ebd2574-b084-4719-9f72-2cab06e166ae" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_5e033156-6005-4431-a0f2-badf9d03ee6f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_5233e454-e4b0-4a2a-9b41-32887d766a63" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_5945d57a-f0cd-4e40-abeb-d2c311500d66" xlink:to="loc_us-gaap_StatementTable_5233e454-e4b0-4a2a-9b41-32887d766a63" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_fa02b885-0018-4f83-9a10-6bd7892db294" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5233e454-e4b0-4a2a-9b41-32887d766a63" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_fa02b885-0018-4f83-9a10-6bd7892db294" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_fa02b885-0018-4f83-9a10-6bd7892db294_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_fa02b885-0018-4f83-9a10-6bd7892db294" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_fa02b885-0018-4f83-9a10-6bd7892db294_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_fa02b885-0018-4f83-9a10-6bd7892db294" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_19db53c4-c126-42f2-9ece-2e0cb16d85ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfSalesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:to="loc_us-gaap_CostOfSalesMember_19db53c4-c126-42f2-9ece-2e0cb16d85ad" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_a199bdcb-90e9-480f-bd3c-d21ef112f199" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_a199bdcb-90e9-480f-bd3c-d21ef112f199" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_0ceeaa22-41a0-4c45-ab48-89417b7b7d41" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_0ceeaa22-41a0-4c45-ab48-89417b7b7d41" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_4bb0bf49-02a2-4532-8c12-7321401c074a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_23af61f2-9d83-4044-aff2-192b8b0a535e" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_4bb0bf49-02a2-4532-8c12-7321401c074a" xlink:type="arc" order="3"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY" xlink:type="extended" id="i1fd2a1cea00746eb9453c24441c6d755_CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITY">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_30b25b0f-5f35-446c-901e-954b022adfcb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_30b25b0f-5f35-446c-901e-954b022adfcb" xlink:to="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_870d39f4-ab96-4f3f-9b80-aa5e3c7ef6c6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:to="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_870d39f4-ab96-4f3f-9b80-aa5e3c7ef6c6" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_77c46451-5255-4e16-b1ac-e6a6c9bb5b99" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:to="loc_us-gaap_NetIncomeLossAttributableToRedeemableNoncontrollingInterest_77c46451-5255-4e16-b1ac-e6a6c9bb5b99" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterest_e3c6edea-27d8-492b-83b3-4c5bc4ebab7c" xlink:href="iaci-20230331.xsd#iaci_OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:to="loc_iaci_OtherComprehensiveIncomeLossNetofTaxAttributabletoRedeemableNoncontrollingInterest_e3c6edea-27d8-492b-83b3-4c5bc4ebab7c" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityAccretionToRedemptionValue_0348bbdb-8924-45e6-bd73-5112e88d69de" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquityAccretionToRedemptionValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:to="loc_us-gaap_TemporaryEquityAccretionToRedemptionValue_0348bbdb-8924-45e6-bd73-5112e88d69de" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TemporaryEquityOtherChanges_7e24b06d-d092-4673-acab-478f9f8350b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TemporaryEquityOtherChanges"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInTemporaryEquityRollForward_44cf2e51-754b-442e-a842-b939c009a20e" xlink:to="loc_us-gaap_TemporaryEquityOtherChanges_7e24b06d-d092-4673-acab-478f9f8350b5" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount_35aad7c3-7a90-4201-b4b8-f9b91aae72c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RedeemableNoncontrollingInterestEquityCarryingAmount"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_30b25b0f-5f35-446c-901e-954b022adfcb" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_3df77e22-b3b2-4634-bff4-7b5b22a5a17e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_3df77e22-b3b2-4634-bff4-7b5b22a5a17e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_e779d329-d32b-4c7e-b8c7-ba4cddeb8b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_SharesIssued_e779d329-d32b-4c7e-b8c7-ba4cddeb8b2d" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_0fca7651-881b-41be-a38a-d436e5b7888f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_NetIncomeLossIncludingPortionAttributableToNonredeemableNoncontrollingInterest_0fca7651-881b-41be-a38a-d436e5b7888f" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_OtherComprehensiveIncomeLossNetofTaxIncludingPortionAttributabletoNonredeemableNoncontrollingInterestTotal_642496e3-16a1-40b5-bf80-0d01240a11d9" xlink:href="iaci-20230331.xsd#iaci_OtherComprehensiveIncomeLossNetofTaxIncludingPortionAttributabletoNonredeemableNoncontrollingInterestTotal"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_iaci_OtherComprehensiveIncomeLossNetofTaxIncludingPortionAttributabletoNonredeemableNoncontrollingInterestTotal_642496e3-16a1-40b5-bf80-0d01240a11d9" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_b9afae2c-a804-4112-a609-accf09ff8d28" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_b9afae2c-a804-4112-a609-accf09ff8d28" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_IssuanceofCommonStockPursuanttoStockBasedAwardsNetofWithholdingTaxes_f69b624f-cd20-4e3a-8187-06b05ccc283a" xlink:href="iaci-20230331.xsd#iaci_IssuanceofCommonStockPursuanttoStockBasedAwardsNetofWithholdingTaxes"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_iaci_IssuanceofCommonStockPursuanttoStockBasedAwardsNetofWithholdingTaxes_f69b624f-cd20-4e3a-8187-06b05ccc283a" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_IssuanceOfCommonStockSharesPursuantToStockBasedAwardsNetOfWithholdingTaxes_8786815d-1d0f-46f4-8202-0716e2b5ea5c" xlink:href="iaci-20230331.xsd#iaci_IssuanceOfCommonStockSharesPursuantToStockBasedAwardsNetOfWithholdingTaxes"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_iaci_IssuanceOfCommonStockSharesPursuantToStockBasedAwardsNetOfWithholdingTaxes_8786815d-1d0f-46f4-8202-0716e2b5ea5c" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_ca1f3231-d5cd-4197-a36d-a7eb5a39d418" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_ca1f3231-d5cd-4197-a36d-a7eb5a39d418" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdjustmentofRedeemableNoncontrollingInteresttoFairValue_0cf7c3fd-5824-42e5-a669-7d1cd02b5b58" xlink:href="iaci-20230331.xsd#iaci_AdjustmentofRedeemableNoncontrollingInteresttoFairValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_iaci_AdjustmentofRedeemableNoncontrollingInteresttoFairValue_0cf7c3fd-5824-42e5-a669-7d1cd02b5b58" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdjustmentsToAdditionalPaidInCapitalAdjustmentToLiquidationValue_1c496499-2d5a-41e7-9e81-fcc36018c9ad" xlink:href="iaci-20230331.xsd#iaci_AdjustmentsToAdditionalPaidInCapitalAdjustmentToLiquidationValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_iaci_AdjustmentsToAdditionalPaidInCapitalAdjustmentToLiquidationValue_1c496499-2d5a-41e7-9e81-fcc36018c9ad" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_395b6b2b-f3dd-4257-9e03-56b7a3e3bcfa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityOther"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_beef9d67-3ae5-4cb9-9f7a-199961c83e86" xlink:to="loc_us-gaap_StockholdersEquityOther_395b6b2b-f3dd-4257-9e03-56b7a3e3bcfa" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_5918e197-dcce-4c49-80a2-c658592c9ab2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_d3ed7f8a-4827-4b6c-b77d-8e0430d0d416" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharesIssued"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_beff62d1-9751-4ad6-a7ec-10c1be1bdbd3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_30b25b0f-5f35-446c-901e-954b022adfcb" xlink:to="loc_us-gaap_StatementTable_beff62d1-9751-4ad6-a7ec-10c1be1bdbd3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_75ff9bf5-d974-4233-97e2-83cc5a930ab8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_beff62d1-9751-4ad6-a7ec-10c1be1bdbd3" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_75ff9bf5-d974-4233-97e2-83cc5a930ab8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_75ff9bf5-d974-4233-97e2-83cc5a930ab8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_75ff9bf5-d974-4233-97e2-83cc5a930ab8" xlink:to="loc_us-gaap_EquityComponentDomain_75ff9bf5-d974-4233-97e2-83cc5a930ab8_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_a60a334c-efb1-47fb-97b0-b20bdc6fce02" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_75ff9bf5-d974-4233-97e2-83cc5a930ab8" xlink:to="loc_us-gaap_EquityComponentDomain_a60a334c-efb1-47fb-97b0-b20bdc6fce02" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RedeemableNoncontrollingInterestsMember_0bccd743-16d9-46bf-be83-acb7ac35f91d" xlink:href="iaci-20230331.xsd#iaci_RedeemableNoncontrollingInterestsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a60a334c-efb1-47fb-97b0-b20bdc6fce02" xlink:to="loc_iaci_RedeemableNoncontrollingInterestsMember_0bccd743-16d9-46bf-be83-acb7ac35f91d" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ParentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a60a334c-efb1-47fb-97b0-b20bdc6fce02" xlink:to="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_92ff4182-d163-4dee-821b-82bb25adb5dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:to="loc_us-gaap_CommonStockMember_92ff4182-d163-4dee-821b-82bb25adb5dd" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_795a48fe-9ced-4f4e-bf60-3f07a4a6b72a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_795a48fe-9ced-4f4e-bf60-3f07a4a6b72a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_f2e9f3d2-1d94-4649-862b-fba4f209e273" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:to="loc_us-gaap_RetainedEarningsMember_f2e9f3d2-1d94-4649-862b-fba4f209e273" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_9e2ea76c-2f9b-4aed-b602-254c3cf67ec8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_9e2ea76c-2f9b-4aed-b602-254c3cf67ec8" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_8ae0f644-6b17-4bb4-b9f5-e1149af7af9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_603050b8-4e01-45ec-bf29-84287ee1527f" xlink:to="loc_us-gaap_TreasuryStockMember_8ae0f644-6b17-4bb4-b9f5-e1149af7af9f" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_ded39813-a872-4d27-a5b0-bf3ca48c489a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_a60a334c-efb1-47fb-97b0-b20bdc6fce02" xlink:to="loc_us-gaap_NoncontrollingInterestMember_ded39813-a872-4d27-a5b0-bf3ca48c489a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_83e02b4f-21ea-41cf-a71d-5a439f81b865" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_beff62d1-9751-4ad6-a7ec-10c1be1bdbd3" xlink:to="loc_us-gaap_StatementClassOfStockAxis_83e02b4f-21ea-41cf-a71d-5a439f81b865" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_83e02b4f-21ea-41cf-a71d-5a439f81b865_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_83e02b4f-21ea-41cf-a71d-5a439f81b865" xlink:to="loc_us-gaap_ClassOfStockDomain_83e02b4f-21ea-41cf-a71d-5a439f81b865_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_61b387f7-c11c-41f4-aa53-847db5743de5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_83e02b4f-21ea-41cf-a71d-5a439f81b865" xlink:to="loc_us-gaap_ClassOfStockDomain_61b387f7-c11c-41f4-aa53-847db5743de5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_1dda7de7-f3f1-4245-96ed-d81eac487066" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_61b387f7-c11c-41f4-aa53-847db5743de5" xlink:to="loc_us-gaap_CommonClassAMember_1dda7de7-f3f1-4245-96ed-d81eac487066" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_8eecfd22-07f3-4791-a69f-8e31454ecce3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassBMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_61b387f7-c11c-41f4-aa53-847db5743de5" xlink:to="loc_us-gaap_CommonClassBMember_8eecfd22-07f3-4791-a69f-8e31454ecce3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_7bf82ceb-f592-4475-af64-56fd53c95f81" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_beff62d1-9751-4ad6-a7ec-10c1be1bdbd3" xlink:to="loc_dei_LegalEntityAxis_7bf82ceb-f592-4475-af64-56fd53c95f81" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_7bf82ceb-f592-4475-af64-56fd53c95f81_default" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_7bf82ceb-f592-4475-af64-56fd53c95f81" xlink:to="loc_dei_EntityDomain_7bf82ceb-f592-4475-af64-56fd53c95f81_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_552fef43-9420-40e9-b0d2-e306b1f26635" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_7bf82ceb-f592-4475-af64-56fd53c95f81" xlink:to="loc_dei_EntityDomain_552fef43-9420-40e9-b0d2-e306b1f26635" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_e0e7e4e9-ff39-4a50-88e7-b8d33f37d509" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_552fef43-9420-40e9-b0d2-e306b1f26635" xlink:to="loc_iaci_AngiIncMember_e0e7e4e9-ff39-4a50-88e7-b8d33f37d509" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_IACMember_b464ad41-8ade-4729-8818-6475e11a3b98" xlink:href="iaci-20230331.xsd#iaci_IACMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_552fef43-9420-40e9-b0d2-e306b1f26635" xlink:to="loc_iaci_IACMember_b464ad41-8ade-4729-8818-6475e11a3b98" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical" xlink:type="extended" id="idf52b4009265468da4fb590f53f606c4_CONSOLIDATEDSTATEMENTOFSHAREHOLDERSEQUITYParenthetical">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_6a62685c-5539-46af-852e-4cf674b7916d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_c08a7fc4-fa35-49dd-9904-e29387189165" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6a62685c-5539-46af-852e-4cf674b7916d" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_c08a7fc4-fa35-49dd-9904-e29387189165" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_d2fd158d-3ed6-4752-aca2-ec2af3f3c622" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6a62685c-5539-46af-852e-4cf674b7916d" xlink:to="loc_us-gaap_StatementTable_d2fd158d-3ed6-4752-aca2-ec2af3f3c622" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_eecd8d87-7b07-4513-af29-340f7410dc9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_d2fd158d-3ed6-4752-aca2-ec2af3f3c622" xlink:to="loc_us-gaap_StatementClassOfStockAxis_eecd8d87-7b07-4513-af29-340f7410dc9f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_eecd8d87-7b07-4513-af29-340f7410dc9f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_eecd8d87-7b07-4513-af29-340f7410dc9f" xlink:to="loc_us-gaap_ClassOfStockDomain_eecd8d87-7b07-4513-af29-340f7410dc9f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_aee9eb11-0ac8-4d0b-a6b6-530f0091aab1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_eecd8d87-7b07-4513-af29-340f7410dc9f" xlink:to="loc_us-gaap_ClassOfStockDomain_aee9eb11-0ac8-4d0b-a6b6-530f0091aab1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassAMember_3628ff18-05c2-4fe2-b22e-423373ed20f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassAMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_aee9eb11-0ac8-4d0b-a6b6-530f0091aab1" xlink:to="loc_us-gaap_CommonClassAMember_3628ff18-05c2-4fe2-b22e-423373ed20f3" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonClassBMember_e1d367b9-83b5-4253-bcbc-ef7d32da97ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonClassBMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_aee9eb11-0ac8-4d0b-a6b6-530f0091aab1" xlink:to="loc_us-gaap_CommonClassBMember_e1d367b9-83b5-4253-bcbc-ef7d32da97ea" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_1e5f3300-7022-476f-9bf4-d19891676011" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_d2fd158d-3ed6-4752-aca2-ec2af3f3c622" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_1e5f3300-7022-476f-9bf4-d19891676011" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_1e5f3300-7022-476f-9bf4-d19891676011_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1e5f3300-7022-476f-9bf4-d19891676011" xlink:to="loc_us-gaap_EquityComponentDomain_1e5f3300-7022-476f-9bf4-d19891676011_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_5bbcf934-68c6-4801-9440-4249c7408ca2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_1e5f3300-7022-476f-9bf4-d19891676011" xlink:to="loc_us-gaap_EquityComponentDomain_5bbcf934-68c6-4801-9440-4249c7408ca2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_95a2567d-472a-414f-bfab-4fe084947ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_5bbcf934-68c6-4801-9440-4249c7408ca2" xlink:to="loc_us-gaap_CommonStockMember_95a2567d-472a-414f-bfab-4fe084947ac2" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFCASHFLOWS" xlink:type="simple" xlink:href="iaci-20230331.xsd#CONSOLIDATEDSTATEMENTOFCASHFLOWS"/>
<link:definitionLink xlink:role="http://www.iac.com/role/CONSOLIDATEDSTATEMENTOFCASHFLOWS" xlink:type="extended" id="i22e1a9e1327d4ea3bf3c9683af23392c_CONSOLIDATEDSTATEMENTOFCASHFLOWS">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_f630d888-d434-43ad-b4f3-374308c5120e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_f630d888-d434-43ad-b4f3-374308c5120e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_6c6dfd2d-2cb6-4ffe-8d46-465c2194f061" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_f630d888-d434-43ad-b4f3-374308c5120e" xlink:to="loc_us-gaap_ProfitLoss_6c6dfd2d-2cb6-4ffe-8d46-465c2194f061" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_f630d888-d434-43ad-b4f3-374308c5120e" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_7cf79760-dcb6-4451-8fcc-e9a6cc2dd786" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_7cf79760-dcb6-4451-8fcc-e9a6cc2dd786" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_217493ba-2d50-484c-a16f-b1bf3a4f7418" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_217493ba-2d50-484c-a16f-b1bf3a4f7418" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_b9b670e9-ccb9-4a13-ab8c-497aae0c7c65" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Depreciation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_Depreciation_b9b670e9-ccb9-4a13-ab8c-497aae0c7c65" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AccountsReceivableCreditLossExpenseReversalandRecovery_d180e085-e322-4e70-9481-6b330d8cd258" xlink:href="iaci-20230331.xsd#iaci_AccountsReceivableCreditLossExpenseReversalandRecovery"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_iaci_AccountsReceivableCreditLossExpenseReversalandRecovery_d180e085-e322-4e70-9481-6b330d8cd258" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_f70bad03-26c3-4812-92bf-fda317912a22" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_f70bad03-26c3-4812-92bf-fda317912a22" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_08f08335-95ae-40d9-b5ad-50db644ce15a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_08f08335-95ae-40d9-b5ad-50db644ce15a" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_LongTermEquitySecuritiesFVNIAndDivestitureOfBusinessGainLoss_8ac05c71-6eaf-4a15-8373-f9a26e16f38c" xlink:href="iaci-20230331.xsd#iaci_LongTermEquitySecuritiesFVNIAndDivestitureOfBusinessGainLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_iaci_LongTermEquitySecuritiesFVNIAndDivestitureOfBusinessGainLoss_8ac05c71-6eaf-4a15-8373-f9a26e16f38c" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAdjustmentOfWarrants_c78b6660-a5b0-49e2-810b-2a43a82e82df" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAdjustmentOfWarrants"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_FairValueAdjustmentOfWarrants_c78b6660-a5b0-49e2-810b-2a43a82e82df" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_ae97cf3b-3b5e-4db5-b822-57cc27c6227d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_ae97cf3b-3b5e-4db5-b822-57cc27c6227d" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash_a7efe1e4-d56e-4965-a875-e02a28006772" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_PensionAndOtherPostretirementBenefitsExpenseReversalOfExpenseNoncash_a7efe1e4-d56e-4965-a875-e02a28006772" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_b19731fe-fde0-4578-8049-2e4717391875" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNoncashIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_b19731fe-fde0-4578-8049-2e4717391875" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_658be717-a42e-4b31-ac3f-a8feaecde5e4" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_9eff7225-4289-42dd-a641-ef854dfa04d0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_9eff7225-4289-42dd-a641-ef854dfa04d0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_0f2f0861-ca4d-4e42-a10d-519eda39bb6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_0f2f0861-ca4d-4e42-a10d-519eda39bb6d" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_6c956672-82c5-4fc3-ae95-e4d85e328376" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInOperatingLeaseLiability"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingLeaseLiability_6c956672-82c5-4fc3-ae95-e4d85e328376" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_8d8c3a10-284b-40fa-848d-58e9eb022597" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_8d8c3a10-284b-40fa-848d-58e9eb022597" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_142879bd-1bfd-431b-826b-b4357145a3dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_142879bd-1bfd-431b-826b-b4357145a3dc" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_2e32dd69-c772-4a5a-ad9e-b71ab5f7b1ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInContractWithCustomerLiability"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_bfb45538-25a2-49f6-b238-83eaa96ed7f3" xlink:to="loc_us-gaap_IncreaseDecreaseInContractWithCustomerLiability_2e32dd69-c772-4a5a-ad9e-b71ab5f7b1ee" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_75b5e23d-5b27-42ee-b79f-d078a8d3773e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_f630d888-d434-43ad-b4f3-374308c5120e" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_75b5e23d-5b27-42ee-b79f-d078a8d3773e" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_59a98039-6643-4593-9ea6-efcccb9446a8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_59a98039-6643-4593-9ea6-efcccb9446a8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_1aff6d5d-3572-42cf-a35c-6acfe4594a57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfAvailableForSaleSecurities_1aff6d5d-3572-42cf-a35c-6acfe4594a57" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireMarketableSecurities_c37ea1ee-9b37-4627-8639-87cb1fdac5ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireMarketableSecurities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_PaymentsToAcquireMarketableSecurities_c37ea1ee-9b37-4627-8639-87cb1fdac5ea" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ProceedsfromDivestitureofBusinessandSaleofLongtermInvestments_cba3f15f-5689-4d45-ad7d-1462cc5b39f2" xlink:href="iaci-20230331.xsd#iaci_ProceedsfromDivestitureofBusinessandSaleofLongtermInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_iaci_ProceedsfromDivestitureofBusinessandSaleofLongtermInvestments_cba3f15f-5689-4d45-ad7d-1462cc5b39f2" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireLongtermInvestments_7ea50a93-6734-490a-9067-cbda272b3529" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireLongtermInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_PaymentsToAcquireLongtermInvestments_7ea50a93-6734-490a-9067-cbda272b3529" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_5f2e4779-749b-4e7d-bf05-e1071d6c62eb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_5f2e4779-749b-4e7d-bf05-e1071d6c62eb" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_d7475a9a-81d4-4a6d-87b6-a300f4ef2d60" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_PaymentsForProceedsFromOtherInvestingActivities_d7475a9a-81d4-4a6d-87b6-a300f4ef2d60" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_acbd3c12-7287-4150-a370-480c86de5cbb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_b42bb9e2-be1f-405b-b766-582883f19a4d" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_acbd3c12-7287-4150-a370-480c86de5cbb" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_dffa8c58-a1f3-445c-84ea-f8eb56ea051f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_dffa8c58-a1f3-445c-84ea-f8eb56ea051f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_580385d4-949e-451c-8a1a-8df68c2a10dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_580385d4-949e-451c-8a1a-8df68c2a10dd" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_cbb03f01-ba37-4b1b-9ef5-c4b41452fed2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_cbb03f01-ba37-4b1b-9ef5-c4b41452fed2" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_c7c4674c-81ad-4550-b264-2fc5a3ec6ae7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_c7c4674c-81ad-4550-b264-2fc5a3ec6ae7" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_ad3b87fb-fc05-44e1-a51d-e786abce0e54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_ad3b87fb-fc05-44e1-a51d-e786abce0e54" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_ce99a8ce-3409-4dc2-a0d8-e3ca9963233c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_2d1944d1-2229-4341-ab37-5995eb75b8ef" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_ce99a8ce-3409-4dc2-a0d8-e3ca9963233c" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_7c71988a-4d20-4ef2-996a-726ff6fe8da6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetCashProvidedByUsedInContinuingOperations"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_NetCashProvidedByUsedInContinuingOperations_7c71988a-4d20-4ef2-996a-726ff6fe8da6" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_0cdc7025-b0af-4d9d-b2a5-fff4aefe217d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_0cdc7025-b0af-4d9d-b2a5-fff4aefe217d" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_70df7d38-0046-4617-b2cb-04e91079fcfc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_70df7d38-0046-4617-b2cb-04e91079fcfc" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_0e7b0d3b-1930-4171-8d2b-8d8449099635" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_0e7b0d3b-1930-4171-8d2b-8d8449099635" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_55791818-cf28-45c5-9cfe-cd1cae3661ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_54465cff-5f16-40bb-a031-35fb8973b116" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_029f4a49-7c49-46c6-baa9-a5ded9ccd757" xlink:to="loc_us-gaap_StatementTable_54465cff-5f16-40bb-a031-35fb8973b116" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_912843e9-4498-4edf-aa0f-ea30a5235460" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_54465cff-5f16-40bb-a031-35fb8973b116" xlink:to="loc_dei_LegalEntityAxis_912843e9-4498-4edf-aa0f-ea30a5235460" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_912843e9-4498-4edf-aa0f-ea30a5235460_default" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_912843e9-4498-4edf-aa0f-ea30a5235460" xlink:to="loc_dei_EntityDomain_912843e9-4498-4edf-aa0f-ea30a5235460_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_86062941-0dd1-4f9c-9a18-40386a42bc22" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_912843e9-4498-4edf-aa0f-ea30a5235460" xlink:to="loc_dei_EntityDomain_86062941-0dd1-4f9c-9a18-40386a42bc22" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_IACMember_a561b0ed-72db-4bd2-a298-dbe8f73fd381" xlink:href="iaci-20230331.xsd#iaci_IACMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_86062941-0dd1-4f9c-9a18-40386a42bc22" xlink:to="loc_iaci_IACMember_a561b0ed-72db-4bd2-a298-dbe8f73fd381" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_86504b78-527d-4958-96aa-5b34d9bea33e" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_86062941-0dd1-4f9c-9a18-40386a42bc22" xlink:to="loc_iaci_AngiIncMember_86504b78-527d-4958-96aa-5b34d9bea33e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusAxis_4d70aded-50d3-4c2c-97c2-461522f07536" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_54465cff-5f16-40bb-a031-35fb8973b116" xlink:to="loc_us-gaap_GranteeStatusAxis_4d70aded-50d3-4c2c-97c2-461522f07536" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_4d70aded-50d3-4c2c-97c2-461522f07536_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GranteeStatusAxis_4d70aded-50d3-4c2c-97c2-461522f07536" xlink:to="loc_us-gaap_GranteeStatusDomain_4d70aded-50d3-4c2c-97c2-461522f07536_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GranteeStatusDomain_b8eb1218-2ca0-41f2-8264-8a01f29242c9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GranteeStatusDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GranteeStatusAxis_4d70aded-50d3-4c2c-97c2-461522f07536" xlink:to="loc_us-gaap_GranteeStatusDomain_b8eb1218-2ca0-41f2-8264-8a01f29242c9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ShareBasedPaymentArrangementIACEmployeesMember_1a7c5afc-1a95-4343-a9a6-076d39a89b6e" xlink:href="iaci-20230331.xsd#iaci_ShareBasedPaymentArrangementIACEmployeesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_b8eb1218-2ca0-41f2-8264-8a01f29242c9" xlink:to="loc_iaci_ShareBasedPaymentArrangementIACEmployeesMember_1a7c5afc-1a95-4343-a9a6-076d39a89b6e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ShareBasedPaymentArrangementAngiIncEmployeesMember_59e08331-b0a2-4fae-87b6-73106d34f3bb" xlink:href="iaci-20230331.xsd#iaci_ShareBasedPaymentArrangementAngiIncEmployeesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GranteeStatusDomain_b8eb1218-2ca0-41f2-8264-8a01f29242c9" xlink:to="loc_iaci_ShareBasedPaymentArrangementAngiIncEmployeesMember_59e08331-b0a2-4fae-87b6-73106d34f3bb" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="extended" id="if5c1314f1565418d8574fdb0a8b066b4_THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EntityWideRevenueMajorCustomerLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_6ce2d8e8-91a0-46e9-a6a4-8fd1135544ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNotionalAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_DerivativeNotionalAmount_6ce2d8e8-91a0-46e9-a6a4-8fd1135544ca" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_df3d220b-d222-4abe-9276-702fb188bda2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_df3d220b-d222-4abe-9276-702fb188bda2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityCurrent_138aa5cd-f43e-43a8-a6d8-3a79b352799b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiabilityCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityCurrent_138aa5cd-f43e-43a8-a6d8-3a79b352799b" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_a174a2e7-0f27-4370-adb2-5a1f60ce7b49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiabilityNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityNoncurrent_a174a2e7-0f27-4370-adb2-5a1f60ce7b49" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_146d6ea5-7a67-408c-9280-46f4504f594a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_ContractWithCustomerLiabilityRevenueRecognized_146d6ea5-7a67-408c-9280-46f4504f594a" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_8fe8f9b1-f247-41fc-a718-c47e9d375426" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_8fe8f9b1-f247-41fc-a718-c47e9d375426" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNet_4d0cf6d1-f9a5-4d8c-850d-201d2750af9c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsReceivableNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_AccountsReceivableNet_4d0cf6d1-f9a5-4d8c-850d-201d2750af9c" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_d382883a-6803-49cb-99b4-51f29f7ee55c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfOperatingSegments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_NumberOfOperatingSegments_d382883a-6803-49cb-99b4-51f29f7ee55c" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideRevenueMajorCustomerLineItems_7b4118f2-67c3-4da4-8ca1-79a47d3495f8" xlink:to="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_ed9da004-5326-46e6-a64c-7411dc1896b9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_DebtInstrumentAxis_ed9da004-5326-46e6-a64c-7411dc1896b9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ed9da004-5326-46e6-a64c-7411dc1896b9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_ed9da004-5326-46e6-a64c-7411dc1896b9" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ed9da004-5326-46e6-a64c-7411dc1896b9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c42c31ec-2824-4717-8b52-244c1e9b379f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_ed9da004-5326-46e6-a64c-7411dc1896b9" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c42c31ec-2824-4717-8b52-244c1e9b379f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithTermLoanBFacilityMember_aee613a3-3be1-4f10-907e-bfbd23eda1b9" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithTermLoanBFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c42c31ec-2824-4717-8b52-244c1e9b379f" xlink:to="loc_iaci_DotdashMeredithTermLoanBFacilityMember_aee613a3-3be1-4f10-907e-bfbd23eda1b9" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_bb2e622a-a732-44fd-8da2-8ff5741266e9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_bb2e622a-a732-44fd-8da2-8ff5741266e9" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_bb2e622a-a732-44fd-8da2-8ff5741266e9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bb2e622a-a732-44fd-8da2-8ff5741266e9" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_bb2e622a-a732-44fd-8da2-8ff5741266e9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7fa1a0d0-5091-484a-81c9-067c69d7807a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_bb2e622a-a732-44fd-8da2-8ff5741266e9" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7fa1a0d0-5091-484a-81c9-067c69d7807a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_eeee4c8f-b9c9-4fb9-933c-e5d15ebcc5ac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7fa1a0d0-5091-484a-81c9-067c69d7807a" xlink:to="loc_us-gaap_InterestRateSwapMember_eeee4c8f-b9c9-4fb9-933c-e5d15ebcc5ac" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_3f750b4a-d544-44c4-a56c-7ef5063d492f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_3f750b4a-d544-44c4-a56c-7ef5063d492f" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_3f750b4a-d544-44c4-a56c-7ef5063d492f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ChangeInAccountingPrincipleMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_3f750b4a-d544-44c4-a56c-7ef5063d492f" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_3f750b4a-d544-44c4-a56c-7ef5063d492f_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingPrincipleMember_40ddcf83-3ea8-4e11-9f68-8ec86ae112a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ChangeInAccountingPrincipleMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_3f750b4a-d544-44c4-a56c-7ef5063d492f" xlink:to="loc_us-gaap_ChangeInAccountingPrincipleMember_40ddcf83-3ea8-4e11-9f68-8ec86ae112a7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ChangeInAccountingPrincipleRecordingRevenueOnNetBasisMember_6944f331-6984-4f41-b3cd-8e4c983f5b44" xlink:href="iaci-20230331.xsd#iaci_ChangeInAccountingPrincipleRecordingRevenueOnNetBasisMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingPrincipleMember_40ddcf83-3ea8-4e11-9f68-8ec86ae112a7" xlink:to="loc_iaci_ChangeInAccountingPrincipleRecordingRevenueOnNetBasisMember_6944f331-6984-4f41-b3cd-8e4c983f5b44" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_SubsegmentsAxis_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e" xlink:to="loc_us-gaap_SubsegmentsDomain_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_98c58438-fb50-4e2a-958f-5989a2c0e316" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_d1d9d3b8-8b5a-4e96-8bb1-c4c19234456e" xlink:to="loc_us-gaap_SubsegmentsDomain_98c58438-fb50-4e2a-958f-5989a2c0e316" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DesktopMember_e3a55db1-b107-4194-9c8d-567a14069dcb" xlink:href="iaci-20230331.xsd#iaci_DesktopMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_98c58438-fb50-4e2a-958f-5989a2c0e316" xlink:to="loc_iaci_DesktopMember_e3a55db1-b107-4194-9c8d-567a14069dcb" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AskMediaGroupMember_b418484d-9131-4409-9a66-14d4bfb57c45" xlink:href="iaci-20230331.xsd#iaci_AskMediaGroupMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_98c58438-fb50-4e2a-958f-5989a2c0e316" xlink:to="loc_iaci_AskMediaGroupMember_b418484d-9131-4409-9a66-14d4bfb57c45" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_0293c681-dc85-4fd2-9838-31f9ee1c8853" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_srt_MajorCustomersAxis_0293c681-dc85-4fd2-9838-31f9ee1c8853" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_0293c681-dc85-4fd2-9838-31f9ee1c8853_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_0293c681-dc85-4fd2-9838-31f9ee1c8853" xlink:to="loc_srt_NameOfMajorCustomerDomain_0293c681-dc85-4fd2-9838-31f9ee1c8853_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_2075b948-8990-4fd1-b2f1-bac6ac263cdf" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_0293c681-dc85-4fd2-9838-31f9ee1c8853" xlink:to="loc_srt_NameOfMajorCustomerDomain_2075b948-8990-4fd1-b2f1-bac6ac263cdf" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_GoogleIncMember_7373c6a1-95ff-4a98-80ee-e0869ae1684f" xlink:href="iaci-20230331.xsd#iaci_GoogleIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_2075b948-8990-4fd1-b2f1-bac6ac263cdf" xlink:to="loc_iaci_GoogleIncMember_7373c6a1-95ff-4a98-80ee-e0869ae1684f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServicesAgreementMember_e03e305e-218c-468b-b8c1-cf42fb5aab7e" xlink:href="iaci-20230331.xsd#iaci_ServicesAgreementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_2075b948-8990-4fd1-b2f1-bac6ac263cdf" xlink:to="loc_iaci_ServicesAgreementMember_e03e305e-218c-468b-b8c1-cf42fb5aab7e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b39ca1bb-cb91-48ae-9344-a2ed260c540b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e8162dd4-cf6c-41a5-b47b-ee2c65e022aa" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b39ca1bb-cb91-48ae-9344-a2ed260c540b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueSegmentMember_841bc008-c9d8-477f-b78a-ebb4376d3e4a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SalesRevenueSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b39ca1bb-cb91-48ae-9344-a2ed260c540b" xlink:to="loc_us-gaap_SalesRevenueSegmentMember_841bc008-c9d8-477f-b78a-ebb4376d3e4a" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_d03474c0-4f2c-4173-9738-3af400d7b89e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccountsReceivableMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_b39ca1bb-cb91-48ae-9344-a2ed260c540b" xlink:to="loc_us-gaap_AccountsReceivableMember_d03474c0-4f2c-4173-9738-3af400d7b89e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_73ba4595-4358-4f26-a5ae-a1b801fa9750" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_73ba4595-4358-4f26-a5ae-a1b801fa9750" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_73ba4595-4358-4f26-a5ae-a1b801fa9750_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_73ba4595-4358-4f26-a5ae-a1b801fa9750" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_73ba4595-4358-4f26-a5ae-a1b801fa9750_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_73b9abf1-e9ce-43d0-a702-9dc445455466" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_73ba4595-4358-4f26-a5ae-a1b801fa9750" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_73b9abf1-e9ce-43d0-a702-9dc445455466" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_d70b7068-4f75-49f5-9024-22fd65f856ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerConcentrationRiskMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_73b9abf1-e9ce-43d0-a702-9dc445455466" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_d70b7068-4f75-49f5-9024-22fd65f856ec" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_83722a29-a1e5-4a28-bba7-a280b7822263" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideRevenueByMajorCustomersByReportingSegmentsTable_da041869-7a03-4200-9f0a-80a6378209c7" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_83722a29-a1e5-4a28-bba7-a280b7822263" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_83722a29-a1e5-4a28-bba7-a280b7822263_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_83722a29-a1e5-4a28-bba7-a280b7822263" xlink:to="loc_us-gaap_SegmentDomain_83722a29-a1e5-4a28-bba7-a280b7822263_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_56fa35df-9dd4-4579-b337-2e55492ed780" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_83722a29-a1e5-4a28-bba7-a280b7822263" xlink:to="loc_us-gaap_SegmentDomain_56fa35df-9dd4-4579-b337-2e55492ed780" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SearchMember_a3bf0599-aa09-43b9-b787-fa9be2511a8f" xlink:href="iaci-20230331.xsd#iaci_SearchMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_56fa35df-9dd4-4579-b337-2e55492ed780" xlink:to="loc_iaci_SearchMember_a3bf0599-aa09-43b9-b787-fa9be2511a8f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_eb411d5e-ddbd-4bcb-bce6-9cfeaa46356d" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_56fa35df-9dd4-4579-b337-2e55492ed780" xlink:to="loc_iaci_DotdashMeredithMember_eb411d5e-ddbd-4bcb-bce6-9cfeaa46356d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_2b5e7233-0c47-424e-add2-058aead5250d" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_56fa35df-9dd4-4579-b337-2e55492ed780" xlink:to="loc_iaci_AngiIncMember_2b5e7233-0c47-424e-add2-058aead5250d" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCapitalizedContractCostsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCapitalizedContractCostsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCapitalizedContractCostsDetails" xlink:type="extended" id="i227bb763037c4949845b180a260a0d90_THECOMPANYANDSUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESCapitalizedContractCostsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostLineItems_2196a985-6534-46f3-98d7-1c05d07a1554" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNetCurrent_a7a6ae35-a3f6-4e39-9e6e-455671c65c4f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostNetCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_2196a985-6534-46f3-98d7-1c05d07a1554" xlink:to="loc_us-gaap_CapitalizedContractCostNetCurrent_a7a6ae35-a3f6-4e39-9e6e-455671c65c4f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNetNoncurrent_3a975c4b-24e5-44ab-8fb7-5ee82b375dce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostNetNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_2196a985-6534-46f3-98d7-1c05d07a1554" xlink:to="loc_us-gaap_CapitalizedContractCostNetNoncurrent_3a975c4b-24e5-44ab-8fb7-5ee82b375dce" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostNet_ccb29cbc-2164-4952-8819-7e5454dfb860" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_2196a985-6534-46f3-98d7-1c05d07a1554" xlink:to="loc_us-gaap_CapitalizedContractCostNet_ccb29cbc-2164-4952-8819-7e5454dfb860" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostTable_01ad94b4-a7db-41c7-ad8b-4160a11ada7a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalizedContractCostLineItems_2196a985-6534-46f3-98d7-1c05d07a1554" xlink:to="loc_us-gaap_CapitalizedContractCostTable_01ad94b4-a7db-41c7-ad8b-4160a11ada7a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostAxis_5b0f7329-6d67-48a2-937a-a323ae65335a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_CapitalizedContractCostTable_01ad94b4-a7db-41c7-ad8b-4160a11ada7a" xlink:to="loc_us-gaap_CapitalizedContractCostAxis_5b0f7329-6d67-48a2-937a-a323ae65335a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_5b0f7329-6d67-48a2-937a-a323ae65335a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_5b0f7329-6d67-48a2-937a-a323ae65335a" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_5b0f7329-6d67-48a2-937a-a323ae65335a_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedContractCostDomain_112bc607-10dc-46ac-866e-505cb21eb0c4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CapitalizedContractCostDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CapitalizedContractCostAxis_5b0f7329-6d67-48a2-937a-a323ae65335a" xlink:to="loc_us-gaap_CapitalizedContractCostDomain_112bc607-10dc-46ac-866e-505cb21eb0c4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CapitalizedSalesCommissionsMember_f38d845e-ad61-423f-9be1-29ad74e1ab36" xlink:href="iaci-20230331.xsd#iaci_CapitalizedSalesCommissionsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_112bc607-10dc-46ac-866e-505cb21eb0c4" xlink:to="loc_iaci_CapitalizedSalesCommissionsMember_f38d845e-ad61-423f-9be1-29ad74e1ab36" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CapitalizedAppStoreFeesMember_cae7b66d-6c67-4cdc-9ea5-c8fd399ab58e" xlink:href="iaci-20230331.xsd#iaci_CapitalizedAppStoreFeesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalizedContractCostDomain_112bc607-10dc-46ac-866e-505cb21eb0c4" xlink:to="loc_iaci_CapitalizedAppStoreFeesMember_cae7b66d-6c67-4cdc-9ea5-c8fd399ab58e" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESNarrativeDetails" xlink:type="extended" id="i1b2cfbac03b648ab87f02fa1b7025072_DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_88fc5ef6-b73f-4618-903a-b5883e43847c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_5dd862a4-2d20-4641-b234-faf6915a157e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCharges"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_88fc5ef6-b73f-4618-903a-b5883e43847c" xlink:to="loc_us-gaap_RestructuringCharges_5dd862a4-2d20-4641-b234-faf6915a157e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_984758d6-4815-4c2e-ba22-4f2bee2b9c9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_88fc5ef6-b73f-4618-903a-b5883e43847c" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_984758d6-4815-4c2e-ba22-4f2bee2b9c9f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_be17525f-bec1-4a5a-9cac-8ad1512b52ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_88fc5ef6-b73f-4618-903a-b5883e43847c" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_be17525f-bec1-4a5a-9cac-8ad1512b52ee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9466644f-557a-49b0-8e07-040f9b958269" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_be17525f-bec1-4a5a-9cac-8ad1512b52ee" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9466644f-557a-49b0-8e07-040f9b958269" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9466644f-557a-49b0-8e07-040f9b958269_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9466644f-557a-49b0-8e07-040f9b958269" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9466644f-557a-49b0-8e07-040f9b958269_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_e5d8de4b-1a0e-48ad-8ce2-6ccea6721247" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9466644f-557a-49b0-8e07-040f9b958269" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_e5d8de4b-1a0e-48ad-8ce2-6ccea6721247" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MeredithCorporationMember_046343e0-ff6b-4042-88c7-f1784760075a" xlink:href="iaci-20230331.xsd#iaci_MeredithCorporationMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_e5d8de4b-1a0e-48ad-8ce2-6ccea6721247" xlink:to="loc_iaci_MeredithCorporationMember_046343e0-ff6b-4042-88c7-f1784760075a" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESDetails" xlink:type="extended" id="i0ef7c445f3a14d629d2fbd0438d340b5_DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringReserveRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:to="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_c9a93166-36be-4e10-9b0d-12f59abe7ab1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringReserve"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:to="loc_us-gaap_RestructuringReserve_c9a93166-36be-4e10-9b0d-12f59abe7ab1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RestructuringChargesNet_8b9db688-42f5-4757-87f2-4ad3d81820ab" xlink:href="iaci-20230331.xsd#iaci_RestructuringChargesNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:to="loc_iaci_RestructuringChargesNet_8b9db688-42f5-4757-87f2-4ad3d81820ab" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAccrualAdjustment1_fdd88f5b-1fe1-42f7-8b58-4ac724e1ef24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringReserveAccrualAdjustment1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:to="loc_us-gaap_RestructuringReserveAccrualAdjustment1_fdd88f5b-1fe1-42f7-8b58-4ac724e1ef24" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRestructuring_ec6c2a4b-0128-4275-9ddc-dd4e5afaedd2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsForRestructuring"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:to="loc_us-gaap_PaymentsForRestructuring_ec6c2a4b-0128-4275-9ddc-dd4e5afaedd2" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveSettledWithoutCash2_8bfdf259-a9af-4bbd-b3ea-be25b8250be0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringReserveSettledWithoutCash2"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringReserveRollForward_962784cd-7535-4d02-a695-ffffb309f4b8" xlink:to="loc_us-gaap_RestructuringReserveSettledWithoutCash2_8bfdf259-a9af-4bbd-b3ea-be25b8250be0" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserve_3ff65684-8b1e-4342-b421-899adfb3319d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringReserve"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_367f2c92-27cd-443f-97d9-eb5965de8466" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCharges"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:to="loc_us-gaap_RestructuringCharges_367f2c92-27cd-443f-97d9-eb5965de8466" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_44849b4d-0766-4eb6-a07f-5a8c91ae4d87" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1_44849b4d-0766-4eb6-a07f-5a8c91ae4d87" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWriteDown_bae7305f-71a5-4cd0-bcac-3dd88fd62316" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InventoryWriteDown"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:to="loc_us-gaap_InventoryWriteDown_bae7305f-71a5-4cd0-bcac-3dd88fd62316" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5afdad84-7f74-4b76-a68f-9e1392f80e15" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_4eac9754-0218-44f3-b57c-7ab52bb5f9bd" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5afdad84-7f74-4b76-a68f-9e1392f80e15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_c8e61156-58f3-423c-b992-f278c75ceb84" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_5afdad84-7f74-4b76-a68f-9e1392f80e15" xlink:to="loc_us-gaap_SubsegmentsAxis_c8e61156-58f3-423c-b992-f278c75ceb84" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_c8e61156-58f3-423c-b992-f278c75ceb84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_c8e61156-58f3-423c-b992-f278c75ceb84" xlink:to="loc_us-gaap_SubsegmentsDomain_c8e61156-58f3-423c-b992-f278c75ceb84_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_58838d03-9e55-4e55-9397-06b1d5150664" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_c8e61156-58f3-423c-b992-f278c75ceb84" xlink:to="loc_us-gaap_SubsegmentsDomain_58838d03-9e55-4e55-9397-06b1d5150664" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DigitalMember_87d923e1-b9f9-4419-9f2f-b46c5594cf15" xlink:href="iaci-20230331.xsd#iaci_DigitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_58838d03-9e55-4e55-9397-06b1d5150664" xlink:to="loc_iaci_DigitalMember_87d923e1-b9f9-4419-9f2f-b46c5594cf15" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PrintMember_2370992f-f07c-480c-95c1-0e5913f971b0" xlink:href="iaci-20230331.xsd#iaci_PrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_58838d03-9e55-4e55-9397-06b1d5150664" xlink:to="loc_iaci_PrintMember_2370992f-f07c-480c-95c1-0e5913f971b0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SubsegmentOtherMember_fe7b3269-8981-431f-bb7f-4627a3764197" xlink:href="iaci-20230331.xsd#iaci_SubsegmentOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_58838d03-9e55-4e55-9397-06b1d5150664" xlink:to="loc_iaci_SubsegmentOtherMember_fe7b3269-8981-431f-bb7f-4627a3764197" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESAllocationofRestructuringCostsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESAllocationofRestructuringCostsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESAllocationofRestructuringCostsDetails" xlink:type="extended" id="i6cd484a2e07b4997b6ead4a126b1b469_DOTDASHMEREDITHRESTRUCTURINGCHARGESTRANSACTIONRELATEDEXPENSESAllocationofRestructuringCostsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_12cd4bd6-375f-4e91-9981-ddb741b32b44" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCosts_62f14082-010a-4cc8-81ce-85d264469f0f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCosts"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_12cd4bd6-375f-4e91-9981-ddb741b32b44" xlink:to="loc_us-gaap_RestructuringCosts_62f14082-010a-4cc8-81ce-85d264469f0f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_563a5562-197a-4632-ab20-311d54f83519" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_12cd4bd6-375f-4e91-9981-ddb741b32b44" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_563a5562-197a-4632-ab20-311d54f83519" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_30a2f406-8351-4826-abc6-504e9afc15ac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_563a5562-197a-4632-ab20-311d54f83519" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_30a2f406-8351-4826-abc6-504e9afc15ac" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_30a2f406-8351-4826-abc6-504e9afc15ac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_30a2f406-8351-4826-abc6-504e9afc15ac" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_30a2f406-8351-4826-abc6-504e9afc15ac_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_30a2f406-8351-4826-abc6-504e9afc15ac" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_9f25f946-f1ec-486d-b82e-2e947ad03bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfSalesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:to="loc_us-gaap_CostOfSalesMember_9f25f946-f1ec-486d-b82e-2e947ad03bf5" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpenseMember_e722ae78-2446-4de9-b4af-84bbe318345b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingAndMarketingExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:to="loc_us-gaap_SellingAndMarketingExpenseMember_e722ae78-2446-4de9-b4af-84bbe318345b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_0aa26690-bb77-4104-96f7-dc4ec1ed0d12" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_0aa26690-bb77-4104-96f7-dc4ec1ed0d12" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_b73d4e33-5eec-4638-8d61-be8e25bf4f38" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ed216907-04cf-4ff7-9b57-6fc56f591569" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_b73d4e33-5eec-4638-8d61-be8e25bf4f38" xlink:type="arc" order="3"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSNarrativeDetails" xlink:type="extended" id="i79bd00e69a774e71b4d9c127d875e65b_FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_NumberOfInvestmentsInMarketableEquitySecurities_b4ea266e-0f6b-4e46-8d4c-86d7d5441b4b" xlink:href="iaci-20230331.xsd#iaci_NumberOfInvestmentsInMarketableEquitySecurities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_NumberOfInvestmentsInMarketableEquitySecurities_b4ea266e-0f6b-4e46-8d4c-86d7d5441b4b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_0d2c683e-4772-4833-8015-4824e2ef40a5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_0d2c683e-4772-4833-8015-4824e2ef40a5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_425f7ad6-b697-4f6d-a5c8-1e3ed06d4fc7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_425f7ad6-b697-4f6d-a5c8-1e3ed06d4fc7" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EquitySecuritiesFVNINumberOfTotalSharesOwned_845cb4ad-93b5-46f0-8df5-36568a7e8297" xlink:href="iaci-20230331.xsd#iaci_EquitySecuritiesFVNINumberOfTotalSharesOwned"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_EquitySecuritiesFVNINumberOfTotalSharesOwned_845cb4ad-93b5-46f0-8df5-36568a7e8297" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EquitySecuritiesFVNINumberOfSharesPurchased_7a02f2e4-3d41-49bb-8772-425abbd81053" xlink:href="iaci-20230331.xsd#iaci_EquitySecuritiesFVNINumberOfSharesPurchased"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_EquitySecuritiesFVNINumberOfSharesPurchased_7a02f2e4-3d41-49bb-8772-425abbd81053" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireEquitySecuritiesFvNi_172d61ba-ff66-45d7-8d88-df56ce94ca30" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireEquitySecuritiesFvNi"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_PaymentsToAcquireEquitySecuritiesFvNi_172d61ba-ff66-45d7-8d88-df56ce94ca30" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_26b12cb2-454f-4c9c-9fc4-c4e2f2674f49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_26b12cb2-454f-4c9c-9fc4-c4e2f2674f49" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_8e60d06c-e0d0-4098-a4d6-66462f420811" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_8e60d06c-e0d0-4098-a4d6-66462f420811" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EquitySecuritiesFVNICumulativeGainLoss_039e425d-8160-4c18-9800-ab4ce4d9cd04" xlink:href="iaci-20230331.xsd#iaci_EquitySecuritiesFVNICumulativeGainLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_EquitySecuritiesFVNICumulativeGainLoss_039e425d-8160-4c18-9800-ab4ce4d9cd04" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SensitivityAnalysisOfEquitySecuritiesFVNIUnrealizedGainLossImpactOfTwoDollarChangeInSharePrice_12c27be4-82ff-4c9b-b81a-d42e24abb8cc" xlink:href="iaci-20230331.xsd#iaci_SensitivityAnalysisOfEquitySecuritiesFVNIUnrealizedGainLossImpactOfTwoDollarChangeInSharePrice"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_SensitivityAnalysisOfEquitySecuritiesFVNIUnrealizedGainLossImpactOfTwoDollarChangeInSharePrice_12c27be4-82ff-4c9b-b81a-d42e24abb8cc" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_c5dbd895-26cb-438e-9fa5-6af607220f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_c5dbd895-26cb-438e-9fa5-6af607220f0e" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentCumulativeAmount_2b59995c-a789-4800-b0c2-747f1f25909a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentCumulativeAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueUpwardPriceAdjustmentCumulativeAmount_2b59995c-a789-4800-b0c2-747f1f25909a" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentCumulativeAmount_158ac81f-ff2a-4719-9eeb-f4ceeaec10fd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentCumulativeAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_EquitySecuritiesWithoutReadilyDeterminableFairValueDownwardPriceAdjustmentCumulativeAmount_158ac81f-ff2a-4719-9eeb-f4ceeaec10fd" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_3eba5eac-2110-498e-a85d-7ac65fa844e1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_3eba5eac-2110-498e-a85d-7ac65fa844e1" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_708633af-160b-4f2e-9cee-f50124447126" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_708633af-160b-4f2e-9cee-f50124447126" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_1ecae8b4-9123-41c1-b915-c8fc50125f11" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_1ecae8b4-9123-41c1-b915-c8fc50125f11" xlink:type="arc" order="15"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLeasehold_4028a6a1-e9bc-4f4f-8cdd-90b5f7b998f1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfLeasehold"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_ImpairmentOfLeasehold_4028a6a1-e9bc-4f4f-8cdd-90b5f7b998f1" xlink:type="arc" order="16"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CarryingAmountOfGoodwillForWhichExcessOfFairValueOverCarryingValueIsLessThan20_397afb15-dc21-47c4-bd14-0510b52fd081" xlink:href="iaci-20230331.xsd#iaci_CarryingAmountOfGoodwillForWhichExcessOfFairValueOverCarryingValueIsLessThan20"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_CarryingAmountOfGoodwillForWhichExcessOfFairValueOverCarryingValueIsLessThan20_397afb15-dc21-47c4-bd14-0510b52fd081" xlink:type="arc" order="17"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CarryingAmountOfIndefiniteLivedIntangibleAssetsForWhichExcessOfFairValueOverCarryingValueIsLessThan20_a3486702-9474-484f-bf92-c407bae25e4f" xlink:href="iaci-20230331.xsd#iaci_CarryingAmountOfIndefiniteLivedIntangibleAssetsForWhichExcessOfFairValueOverCarryingValueIsLessThan20"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_iaci_CarryingAmountOfIndefiniteLivedIntangibleAssetsForWhichExcessOfFairValueOverCarryingValueIsLessThan20_a3486702-9474-484f-bf92-c407bae25e4f" xlink:type="arc" order="18"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_a4a07a17-942c-49f7-ba66-2087e410d1cf" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_bdbd3202-84f1-4bf5-8b69-7c4ed2113142" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_bdbd3202-84f1-4bf5-8b69-7c4ed2113142" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_bdbd3202-84f1-4bf5-8b69-7c4ed2113142_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_bdbd3202-84f1-4bf5-8b69-7c4ed2113142" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_bdbd3202-84f1-4bf5-8b69-7c4ed2113142_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_28ffda67-e62d-46df-b8e9-c65d797d46c2" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_bdbd3202-84f1-4bf5-8b69-7c4ed2113142" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_28ffda67-e62d-46df-b8e9-c65d797d46c2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MGMMember_776b9641-1ece-4868-a8ad-1ba86b6c53bb" xlink:href="iaci-20230331.xsd#iaci_MGMMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_28ffda67-e62d-46df-b8e9-c65d797d46c2" xlink:to="loc_iaci_MGMMember_776b9641-1ece-4868-a8ad-1ba86b6c53bb" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_TuroMember_20b6e74d-3057-4662-9b45-2525ae8d422a" xlink:href="iaci-20230331.xsd#iaci_TuroMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_28ffda67-e62d-46df-b8e9-c65d797d46c2" xlink:to="loc_iaci_TuroMember_20b6e74d-3057-4662-9b45-2525ae8d422a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_43f74ed9-fa61-46c9-93a6-7a2674ed50af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_43f74ed9-fa61-46c9-93a6-7a2674ed50af" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_43f74ed9-fa61-46c9-93a6-7a2674ed50af_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_43f74ed9-fa61-46c9-93a6-7a2674ed50af" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_43f74ed9-fa61-46c9-93a6-7a2674ed50af_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_397f7caa-ba69-406b-90e7-0da73d59ade3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_43f74ed9-fa61-46c9-93a6-7a2674ed50af" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_397f7caa-ba69-406b-90e7-0da73d59ade3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_66fc9191-f5c1-454f-89b8-5924500c9dee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_397f7caa-ba69-406b-90e7-0da73d59ade3" xlink:to="loc_us-gaap_SubsequentEventMember_66fc9191-f5c1-454f-89b8-5924500c9dee" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_384a3118-5e23-43c7-82ff-f9debc9ed738" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:to="loc_srt_OwnershipAxis_384a3118-5e23-43c7-82ff-f9debc9ed738" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_384a3118-5e23-43c7-82ff-f9debc9ed738_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_384a3118-5e23-43c7-82ff-f9debc9ed738" xlink:to="loc_srt_OwnershipDomain_384a3118-5e23-43c7-82ff-f9debc9ed738_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_78dc15ba-c8ca-439e-b869-4981b0b5a67a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_OwnershipDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_384a3118-5e23-43c7-82ff-f9debc9ed738" xlink:to="loc_srt_OwnershipDomain_78dc15ba-c8ca-439e-b869-4981b0b5a67a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MGMMember_0834e5e3-acce-4036-b8bc-e4cc0521982f" xlink:href="iaci-20230331.xsd#iaci_MGMMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_78dc15ba-c8ca-439e-b869-4981b0b5a67a" xlink:to="loc_iaci_MGMMember_0834e5e3-acce-4036-b8bc-e4cc0521982f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_43257c3b-261b-4f77-82d3-9650c343245a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_43257c3b-261b-4f77-82d3-9650c343245a" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_43257c3b-261b-4f77-82d3-9650c343245a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_43257c3b-261b-4f77-82d3-9650c343245a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_43257c3b-261b-4f77-82d3-9650c343245a_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f2cce833-4530-474c-8b83-c69776448024" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_43257c3b-261b-4f77-82d3-9650c343245a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f2cce833-4530-474c-8b83-c69776448024" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MeredithCorporationMember_35879495-12d6-4dd0-affb-93f95e21e471" xlink:href="iaci-20230331.xsd#iaci_MeredithCorporationMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_f2cce833-4530-474c-8b83-c69776448024" xlink:to="loc_iaci_MeredithCorporationMember_35879495-12d6-4dd0-affb-93f95e21e471" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_a538c3f9-b569-4802-a22a-dd5d589e3fbe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_470808be-5541-461b-a254-d1114fac9e6b" xlink:to="loc_us-gaap_SubsegmentsAxis_a538c3f9-b569-4802-a22a-dd5d589e3fbe" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_a538c3f9-b569-4802-a22a-dd5d589e3fbe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_a538c3f9-b569-4802-a22a-dd5d589e3fbe" xlink:to="loc_us-gaap_SubsegmentsDomain_a538c3f9-b569-4802-a22a-dd5d589e3fbe_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_954764f5-b157-4027-84f9-833edbcd7419" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_a538c3f9-b569-4802-a22a-dd5d589e3fbe" xlink:to="loc_us-gaap_SubsegmentsDomain_954764f5-b157-4027-84f9-833edbcd7419" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MosaicGroupMember_432afefe-a9fb-4e41-9346-9d1a6d158a25" xlink:href="iaci-20230331.xsd#iaci_MosaicGroupMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_954764f5-b157-4027-84f9-833edbcd7419" xlink:to="loc_iaci_MosaicGroupMember_432afefe-a9fb-4e41-9346-9d1a6d158a25" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_9fecd05d-7fc8-49de-aabe-1dea40d2283f" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_954764f5-b157-4027-84f9-833edbcd7419" xlink:to="loc_iaci_DotdashMeredithMember_9fecd05d-7fc8-49de-aabe-1dea40d2283f" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCurrentAvailableforSaleMarketableSecuritiesDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCurrentAvailableforSaleMarketableSecuritiesDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCurrentAvailableforSaleMarketableSecuritiesDetails" xlink:type="extended" id="i39e295b5134643188e9b1402f7a0289a_FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCurrentAvailableforSaleMarketableSecuritiesDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1f57609b-ad9b-4704-b0e5-ae7ada14f0cf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1f57609b-ad9b-4704-b0e5-ae7ada14f0cf" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_ab9799e1-f9a9-40fc-9fac-e99ee7c745df" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_ab9799e1-f9a9-40fc-9fac-e99ee7c745df" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_d99869ef-35cb-49db-ae50-5d3de6fe640b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_d99869ef-35cb-49db-ae50-5d3de6fe640b" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_74ba311a-51e2-46df-a347-1f771becf783" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_74ba311a-51e2-46df-a347-1f771becf783" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_21ec4e6d-2483-449d-99a8-e94d1840934e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_fa40d47c-af26-4805-87ee-99ad142901f3" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_21ec4e6d-2483-449d-99a8-e94d1840934e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_a58a5e57-2db5-4f2a-9af6-3baaf39126cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FinancialInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_21ec4e6d-2483-449d-99a8-e94d1840934e" xlink:to="loc_us-gaap_FinancialInstrumentAxis_a58a5e57-2db5-4f2a-9af6-3baaf39126cb" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a58a5e57-2db5-4f2a-9af6-3baaf39126cb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_a58a5e57-2db5-4f2a-9af6-3baaf39126cb" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a58a5e57-2db5-4f2a-9af6-3baaf39126cb_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a65e4e97-a061-4015-a85a-240f0d6aca65" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_a58a5e57-2db5-4f2a-9af6-3baaf39126cb" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a65e4e97-a061-4015-a85a-240f0d6aca65" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_c723e07c-ef9f-4e73-98e5-ed0f7789310a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USTreasurySecuritiesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_a65e4e97-a061-4015-a85a-240f0d6aca65" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_c723e07c-ef9f-4e73-98e5-ed0f7789310a" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended" id="i800ba1a928244e76a31ac8bd50084c82_FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSAssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_9727b575-81f3-4c6e-84e3-053c5d4fcac8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_9727b575-81f3-4c6e-84e3-053c5d4fcac8" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_81eff703-5877-4722-9dcf-e6b887012775" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_81eff703-5877-4722-9dcf-e6b887012775" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_4a8ef80b-acff-41be-9fef-5586c8341331" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_4a8ef80b-acff-41be-9fef-5586c8341331" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_71fb5165-8f7c-41f7-82d6-5f0d69f0c0da" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_71fb5165-8f7c-41f7-82d6-5f0d69f0c0da" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_566a9738-fe3a-45f6-b62a-84128d9663ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_566a9738-fe3a-45f6-b62a-84128d9663ea" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_4e1410bd-3bb3-425a-a906-e9b2265caf66" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherAssetsNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_4e1410bd-3bb3-425a-a906-e9b2265caf66" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_4f9fd7f9-176f-47c6-a34b-da3a4dae8f85" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetsFairValueDisclosure"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_fe1cbe80-4c43-46c6-b0f4-a5792ce8a837" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_4f9fd7f9-176f-47c6-a34b-da3a4dae8f85" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_82ae0c12-0c05-4e6b-9a19-23aae500ab43" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_9727b575-81f3-4c6e-84e3-053c5d4fcac8" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_82ae0c12-0c05-4e6b-9a19-23aae500ab43" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_252bfef2-9155-440c-94b0-1712c55521d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeLiabilities"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_82ae0c12-0c05-4e6b-9a19-23aae500ab43" xlink:to="loc_us-gaap_DerivativeLiabilities_252bfef2-9155-440c-94b0-1712c55521d2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eb2a18c1-f7f0-41b4-82b4-e57186b04d45" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_9727b575-81f3-4c6e-84e3-053c5d4fcac8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eb2a18c1-f7f0-41b4-82b4-e57186b04d45" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_8d75c429-e34f-46ca-baf4-bad0020d5b13" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByAssetClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eb2a18c1-f7f0-41b4-82b4-e57186b04d45" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_8d75c429-e34f-46ca-baf4-bad0020d5b13" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_8d75c429-e34f-46ca-baf4-bad0020d5b13_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_8d75c429-e34f-46ca-baf4-bad0020d5b13" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_8d75c429-e34f-46ca-baf4-bad0020d5b13_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_8d75c429-e34f-46ca-baf4-bad0020d5b13" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_03f1a651-f056-45a8-a5cc-153df663b5d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MoneyMarketFundsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:to="loc_us-gaap_MoneyMarketFundsMember_03f1a651-f056-45a8-a5cc-153df663b5d6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_3beb77e7-1946-4345-a705-507c6ed87d84" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_USTreasurySecuritiesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_3beb77e7-1946-4345-a705-507c6ed87d84" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankTimeDepositsMember_1ac3774c-76b0-4306-939f-56a0914d3fca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BankTimeDepositsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:to="loc_us-gaap_BankTimeDepositsMember_1ac3774c-76b0-4306-939f-56a0914d3fca" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_8e0e51d8-7559-418a-b326-ac53ce946bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_c976c4f2-f2c4-49e4-909c-b60eb9554c9e" xlink:to="loc_us-gaap_WarrantMember_8e0e51d8-7559-418a-b326-ac53ce946bdd" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c5987836-69d1-4396-8461-5dedf26d7caa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_eb2a18c1-f7f0-41b4-82b4-e57186b04d45" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c5987836-69d1-4396-8461-5dedf26d7caa" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5987836-69d1-4396-8461-5dedf26d7caa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c5987836-69d1-4396-8461-5dedf26d7caa" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5987836-69d1-4396-8461-5dedf26d7caa_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b0da5cf-09f1-4f7a-9bcd-62b884aa40c4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_c5987836-69d1-4396-8461-5dedf26d7caa" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b0da5cf-09f1-4f7a-9bcd-62b884aa40c4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_1bf80f43-c611-435a-ad55-696501ce9ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel1Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b0da5cf-09f1-4f7a-9bcd-62b884aa40c4" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_1bf80f43-c611-435a-ad55-696501ce9ba8" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_f8bc9982-9e03-4761-a176-6c500f28858f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel2Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b0da5cf-09f1-4f7a-9bcd-62b884aa40c4" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_f8bc9982-9e03-4761-a176-6c500f28858f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_0a03dbb9-55b4-4c47-b854-56ed438f6011" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel3Member"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b0da5cf-09f1-4f7a-9bcd-62b884aa40c4" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_0a03dbb9-55b4-4c47-b854-56ed438f6011" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails" xlink:type="extended" id="i87989ab24cd04d749f2e90194dff712a_FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonaRecurringBasisDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_4d994274-bf8c-4e3e-8774-dd7a82426cbe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_ee1029e3-2952-4c8b-ae2e-3f918c2bc00f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_4d994274-bf8c-4e3e-8774-dd7a82426cbe" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_ee1029e3-2952-4c8b-ae2e-3f918c2bc00f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_87fc060c-7731-4c0d-bfe6-545959728ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_ee1029e3-2952-4c8b-ae2e-3f918c2bc00f" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_87fc060c-7731-4c0d-bfe6-545959728ae0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_ec8882ed-38ea-48ab-b996-352ff04a04c9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_ee1029e3-2952-4c8b-ae2e-3f918c2bc00f" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_ec8882ed-38ea-48ab-b996-352ff04a04c9" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_f4d2aff8-0af3-491f-bc59-1ec30541632f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_e7f89188-24d3-4325-b8fe-cca536798b24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_4d994274-bf8c-4e3e-8774-dd7a82426cbe" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_e7f89188-24d3-4325-b8fe-cca536798b24" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_31b80a9d-40ec-4c5e-abee-9a3eb3aacc69" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_e7f89188-24d3-4325-b8fe-cca536798b24" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_31b80a9d-40ec-4c5e-abee-9a3eb3aacc69" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_db674ab5-7fe9-4703-b059-d9c7a1c59bfe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_e7f89188-24d3-4325-b8fe-cca536798b24" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_db674ab5-7fe9-4703-b059-d9c7a1c59bfe" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_c640e8be-83ac-41d8-9850-650a53999a3e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_baf4bfb1-a132-44d4-b8c5-ab3360ffd948" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationLineItems_4d994274-bf8c-4e3e-8774-dd7a82426cbe" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_baf4bfb1-a132-44d4-b8c5-ab3360ffd948" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_faf96556-a0de-40ea-b9ff-5354d152a98d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByAssetClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_baf4bfb1-a132-44d4-b8c5-ab3360ffd948" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_faf96556-a0de-40ea-b9ff-5354d152a98d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_faf96556-a0de-40ea-b9ff-5354d152a98d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_faf96556-a0de-40ea-b9ff-5354d152a98d" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_faf96556-a0de-40ea-b9ff-5354d152a98d_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_254708cb-246a-454d-b4b9-f6bd84efa1ab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_faf96556-a0de-40ea-b9ff-5354d152a98d" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_254708cb-246a-454d-b4b9-f6bd84efa1ab" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_ea34cb46-256d-438c-85e5-21832fd72af0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WarrantMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_254708cb-246a-454d-b4b9-f6bd84efa1ab" xlink:to="loc_us-gaap_WarrantMember_ea34cb46-256d-438c-85e5-21832fd72af0" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_45b0aac3-00ca-4a08-9abf-285d667a9bb9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTable_baf4bfb1-a132-44d4-b8c5-ab3360ffd948" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_45b0aac3-00ca-4a08-9abf-285d667a9bb9" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_45b0aac3-00ca-4a08-9abf-285d667a9bb9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_45b0aac3-00ca-4a08-9abf-285d667a9bb9" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_45b0aac3-00ca-4a08-9abf-285d667a9bb9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_30d52e34-09c9-4e48-b784-b69eeb96e782" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_45b0aac3-00ca-4a08-9abf-285d667a9bb9" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_30d52e34-09c9-4e48-b784-b69eeb96e782" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ContingentConsiderationArrangementMember_da8f9327-a49d-4a79-a671-6fc641d43497" xlink:href="iaci-20230331.xsd#iaci_ContingentConsiderationArrangementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_30d52e34-09c9-4e48-b784-b69eeb96e782" xlink:to="loc_iaci_ContingentConsiderationArrangementMember_da8f9327-a49d-4a79-a671-6fc641d43497" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCarryingValueandFairValueofFinancialInstrumentsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCarryingValueandFairValueofFinancialInstrumentsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCarryingValueandFairValueofFinancialInstrumentsDetails" xlink:type="extended" id="i5721e77d7d344e02a9bb0eeb1aa4a3c8_FINANCIALINSTRUMENTSANDFAIRVALUEMEASUREMENTSCarryingValueandFairValueofFinancialInstrumentsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_e92a85d0-1633-49d2-887a-f2572fa9fe56" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_2b98e95d-5f98-42ff-a44e-de946e1b0bd3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_e92a85d0-1633-49d2-887a-f2572fa9fe56" xlink:to="loc_us-gaap_LongTermDebtCurrent_2b98e95d-5f98-42ff-a44e-de946e1b0bd3" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_daf82f9e-527c-4ce2-8918-cbb20e7da47e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_e92a85d0-1633-49d2-887a-f2572fa9fe56" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_daf82f9e-527c-4ce2-8918-cbb20e7da47e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c053b0b5-b0f8-4e27-83f4-33eb633b6586" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_e92a85d0-1633-49d2-887a-f2572fa9fe56" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_c053b0b5-b0f8-4e27-83f4-33eb633b6586" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20d8b339-6ba5-40fb-b834-212da3555fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_e92a85d0-1633-49d2-887a-f2572fa9fe56" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20d8b339-6ba5-40fb-b834-212da3555fb4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_a6c24bed-9804-4eaa-969d-99785c2bb3a9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_20d8b339-6ba5-40fb-b834-212da3555fb4" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_a6c24bed-9804-4eaa-969d-99785c2bb3a9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a6c24bed-9804-4eaa-969d-99785c2bb3a9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_a6c24bed-9804-4eaa-969d-99785c2bb3a9" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a6c24bed-9804-4eaa-969d-99785c2bb3a9_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c255efb0-eae8-4057-809c-bb58a19a4d1c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_a6c24bed-9804-4eaa-969d-99785c2bb3a9" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c255efb0-eae8-4057-809c-bb58a19a4d1c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_4984ebe2-1f11-43c5-a896-c11319d327ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c255efb0-eae8-4057-809c-bb58a19a4d1c" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_4984ebe2-1f11-43c5-a896-c11319d327ea" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_a729398d-a33b-4a6a-b575-c4e1df2e4ef5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c255efb0-eae8-4057-809c-bb58a19a4d1c" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_a729398d-a33b-4a6a-b575-c4e1df2e4ef5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ac5d95cb-1774-4bb2-b739-93fed97f3d31" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_c255efb0-eae8-4057-809c-bb58a19a4d1c" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ac5d95cb-1774-4bb2-b739-93fed97f3d31" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/LONGTERMDEBTSummaryDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#LONGTERMDEBTSummaryDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/LONGTERMDEBTSummaryDetails" xlink:type="extended" id="if4971a54a4fd470d87c1f4f54b2bc58e_LONGTERMDEBTSummaryDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_149a0dee-7610-4498-b52f-1f1e416e9ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_149a0dee-7610-4498-b52f-1f1e416e9ac7" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_19d11a2d-7037-4c1a-8a12-681da8a5bbb5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtCurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_LongTermDebtCurrent_19d11a2d-7037-4c1a-8a12-681da8a5bbb5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_6552f41c-61a8-4934-8fcb-2aeba14fa113" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_6552f41c-61a8-4934-8fcb-2aeba14fa113" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_12dc19f6-cc73-45e3-b2d6-14a0b165108e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsGross"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_12dc19f6-cc73-45e3-b2d6-14a0b165108e" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_cb80e07f-17b8-4c8e-ad1f-a1b639c3cd90" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtNoncurrent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_cb80e07f-17b8-4c8e-ad1f-a1b639c3cd90" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_27205421-20a3-4417-ac85-7ffa1093e478" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_27205421-20a3-4417-ac85-7ffa1093e478" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_e3a65626-93f7-42e8-85f7-beae86d0932e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_04754ddc-d477-47e8-a7a1-0ef261ca63b0" xlink:to="loc_us-gaap_DebtInstrumentTable_e3a65626-93f7-42e8-85f7-beae86d0932e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_c27dd040-4a29-4f6d-852f-9843edb21d28" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e3a65626-93f7-42e8-85f7-beae86d0932e" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_c27dd040-4a29-4f6d-852f-9843edb21d28" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_c27dd040-4a29-4f6d-852f-9843edb21d28_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c27dd040-4a29-4f6d-852f-9843edb21d28" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_c27dd040-4a29-4f6d-852f-9843edb21d28_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_db0b4045-600c-47bf-a81e-d15b81a0a93a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_c27dd040-4a29-4f6d-852f-9843edb21d28" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_db0b4045-600c-47bf-a81e-d15b81a0a93a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember_fbd7aa9f-66c9-461b-b24b-33a70a2c987f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansPayableMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_db0b4045-600c-47bf-a81e-d15b81a0a93a" xlink:to="loc_us-gaap_LoansPayableMember_fbd7aa9f-66c9-461b-b24b-33a70a2c987f" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_cb0d789c-45d5-474d-9c59-99fda2469f86" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_db0b4045-600c-47bf-a81e-d15b81a0a93a" xlink:to="loc_us-gaap_SeniorNotesMember_cb0d789c-45d5-474d-9c59-99fda2469f86" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e3a65626-93f7-42e8-85f7-beae86d0932e" xlink:to="loc_us-gaap_DebtInstrumentAxis_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cb90a890-9466-45b7-888c-e94d5f819088" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_b4635ca3-40f5-4ef7-bd53-24cbb7b7f66a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cb90a890-9466-45b7-888c-e94d5f819088" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithTermLoanAFacilityMember_bd4bf322-0697-4250-a0a2-59fbaa3172f2" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithTermLoanAFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cb90a890-9466-45b7-888c-e94d5f819088" xlink:to="loc_iaci_DotdashMeredithTermLoanAFacilityMember_bd4bf322-0697-4250-a0a2-59fbaa3172f2" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithTermLoanBFacilityMember_29ec7269-d6ba-4a6e-b611-6bee10b6c322" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithTermLoanBFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cb90a890-9466-45b7-888c-e94d5f819088" xlink:to="loc_iaci_DotdashMeredithTermLoanBFacilityMember_29ec7269-d6ba-4a6e-b611-6bee10b6c322" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ANGI3875SeniorNotesMember_7fe77975-6416-4fd6-bf3b-60c0228524a3" xlink:href="iaci-20230331.xsd#iaci_ANGI3875SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cb90a890-9466-45b7-888c-e94d5f819088" xlink:to="loc_iaci_ANGI3875SeniorNotesMember_7fe77975-6416-4fd6-bf3b-60c0228524a3" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_7ff47611-fd28-4b18-a91f-d1ac378b35de" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e3a65626-93f7-42e8-85f7-beae86d0932e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_7ff47611-fd28-4b18-a91f-d1ac378b35de" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_7ff47611-fd28-4b18-a91f-d1ac378b35de_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7ff47611-fd28-4b18-a91f-d1ac378b35de" xlink:to="loc_us-gaap_SegmentDomain_7ff47611-fd28-4b18-a91f-d1ac378b35de_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_551d87c6-6cc8-4543-9a97-947138465825" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7ff47611-fd28-4b18-a91f-d1ac378b35de" xlink:to="loc_us-gaap_SegmentDomain_551d87c6-6cc8-4543-9a97-947138465825" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_710e681d-e01a-49fa-82dd-59bc8a95f0bb" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_551d87c6-6cc8-4543-9a97-947138465825" xlink:to="loc_iaci_DotdashMeredithMember_710e681d-e01a-49fa-82dd-59bc8a95f0bb" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_2268edc0-2e68-4ce7-b561-571135002bc7" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_551d87c6-6cc8-4543-9a97-947138465825" xlink:to="loc_iaci_AngiIncMember_2268edc0-2e68-4ce7-b561-571135002bc7" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#LONGTERMDEBTNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="extended" id="i76ac5336d55048318dbd869c5d7e63f0_LONGTERMDEBTNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_e3d3bf22-fb46-4b21-8b9d-1637e0739931" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTerm"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentTerm_e3d3bf22-fb46-4b21-8b9d-1637e0739931" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_09008485-87d9-425d-9b69-c6856c0e7c8f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_09008485-87d9-425d-9b69-c6856c0e7c8f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_64e03bab-208d-4612-b72d-63ee3d69e688" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_64e03bab-208d-4612-b72d-63ee3d69e688" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentAdjustmentToInterestRate_f9973de5-309d-4fb0-988e-7b23322a9235" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentAdjustmentToInterestRate"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentAdjustmentToInterestRate_f9973de5-309d-4fb0-988e-7b23322a9235" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentAdjustmentToInterestRateTwo_df09a8fa-4c42-4ebb-acfe-51ac548e7f2e" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentAdjustmentToInterestRateTwo"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentAdjustmentToInterestRateTwo_df09a8fa-4c42-4ebb-acfe-51ac548e7f2e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentAdjustmentToInterestRateThree_a8221fe4-6c07-4c4c-b189-a3b32747d980" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentAdjustmentToInterestRateThree"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentAdjustmentToInterestRateThree_a8221fe4-6c07-4c4c-b189-a3b32747d980" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_37a13f8f-6a60-416b-b298-6b3b19d892ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_37a13f8f-6a60-416b-b298-6b3b19d892ec" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_39c6c385-6750-48c9-97ba-cc8261b74b6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_39c6c385-6750-48c9-97ba-cc8261b74b6d" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_a03815a3-7633-47c5-b834-113a5f525d14" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_a03815a3-7633-47c5-b834-113a5f525d14" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_861fb0bb-13ae-40f2-b27d-19b0c4bf81a1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNotionalAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DerivativeNotionalAmount_861fb0bb-13ae-40f2-b27d-19b0c4bf81a1" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_af2197ca-6a25-4504-bf4b-488538cd3dc4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_af2197ca-6a25-4504-bf4b-488538cd3dc4" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_bdd1318b-97b5-4b57-8f5f-340503d435fd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax_bdd1318b-97b5-4b57-8f5f-340503d435fd" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsInHedgesLiabilitiesAtFairValue_4d11aaaa-4d76-4392-85f2-ba626bf273c2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentsInHedgesLiabilitiesAtFairValue"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DerivativeInstrumentsInHedgesLiabilitiesAtFairValue_4d11aaaa-4d76-4392-85f2-ba626bf273c2" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_0dcfc1a2-a4cf-451a-ba58-46f90811bb9d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet_0dcfc1a2-a4cf-451a-ba58-46f90811bb9d" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_efb0437a-5216-4349-a3aa-983bc70d3f28" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCredit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_LineOfCredit_efb0437a-5216-4349-a3aa-983bc70d3f28" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_b9a7e730-fa0f-428d-b3ef-d55f58af4ccb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_b9a7e730-fa0f-428d-b3ef-d55f58af4ccb" xlink:type="arc" order="15"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantMinimumAmountToBeDrawn_99c21842-223f-482f-bad1-6b7514497218" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantMinimumAmountToBeDrawn"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantMinimumAmountToBeDrawn_99c21842-223f-482f-bad1-6b7514497218" xlink:type="arc" order="16"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantPercentageOfOutstandingFace_59b0b061-fed7-4363-b88e-829c79f0306b" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantPercentageOfOutstandingFace"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantPercentageOfOutstandingFace_59b0b061-fed7-4363-b88e-829c79f0306b" xlink:type="arc" order="17"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantTermsOutstandingFaceAmountOfUndrawnLettersOfCreditMinimum_435d2ef2-0513-4554-a531-f24da4e51de3" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantTermsOutstandingFaceAmountOfUndrawnLettersOfCreditMinimum"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantTermsOutstandingFaceAmountOfUndrawnLettersOfCreditMinimum_435d2ef2-0513-4554-a531-f24da4e51de3" xlink:type="arc" order="18"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantTermsNetLeverageRatioNettingAmountMaximum_be4e1ac6-04d9-4e85-b413-1dbc47741a33" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantTermsNetLeverageRatioNettingAmountMaximum"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantTermsNetLeverageRatioNettingAmountMaximum_be4e1ac6-04d9-4e85-b413-1dbc47741a33" xlink:type="arc" order="19"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatio_5a46a8a1-bf50-4a3d-97e9-8c6869d1ed86" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatio"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatio_5a46a8a1-bf50-4a3d-97e9-8c6869d1ed86" xlink:type="arc" order="20"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatioThatWouldLimitDividends_3cb833bd-535d-40c7-9afc-28de219173ae" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatioThatWouldLimitDividends"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantConsolidatedNetLeverageRatioThatWouldLimitDividends_3cb833bd-535d-40c7-9afc-28de219173ae" xlink:type="arc" order="21"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CreditAgreementCapitalContributions_464561e4-afbe-4300-a155-5c6d36bc0de4" xlink:href="iaci-20230331.xsd#iaci_CreditAgreementCapitalContributions"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_CreditAgreementCapitalContributions_464561e4-afbe-4300-a155-5c6d36bc0de4" xlink:type="arc" order="22"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DebtInstrumentCovenantLeverageRatioMaximum_05c15c21-4921-455e-a96e-54c553015b8a" xlink:href="iaci-20230331.xsd#iaci_DebtInstrumentCovenantLeverageRatioMaximum"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_iaci_DebtInstrumentCovenantLeverageRatioMaximum_05c15c21-4921-455e-a96e-54c553015b8a" xlink:type="arc" order="23"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_415715fd-33d5-4f86-9a46-4941569102fa" xlink:to="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_97c7020b-f117-4463-a775-6c09cab02ec7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_DebtInstrumentAxis_97c7020b-f117-4463-a775-6c09cab02ec7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_97c7020b-f117-4463-a775-6c09cab02ec7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_97c7020b-f117-4463-a775-6c09cab02ec7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_97c7020b-f117-4463-a775-6c09cab02ec7_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7f31341a-66b5-4c6b-873d-72d424137037" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_97c7020b-f117-4463-a775-6c09cab02ec7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7f31341a-66b5-4c6b-873d-72d424137037" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithCreditAgreementMember_be5ba072-0fea-468d-9bd4-55710fb7bd25" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithCreditAgreementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f31341a-66b5-4c6b-873d-72d424137037" xlink:to="loc_iaci_DotdashMeredithCreditAgreementMember_be5ba072-0fea-468d-9bd4-55710fb7bd25" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithTermLoanAFacilityMember_361614cc-3af4-4be9-84f6-f4d3eb2fc3a0" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithTermLoanAFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_DotdashMeredithCreditAgreementMember_be5ba072-0fea-468d-9bd4-55710fb7bd25" xlink:to="loc_iaci_DotdashMeredithTermLoanAFacilityMember_361614cc-3af4-4be9-84f6-f4d3eb2fc3a0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithTermLoanBFacilityMember_f032b087-f253-4e16-aafb-3f07755d36dd" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithTermLoanBFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_DotdashMeredithCreditAgreementMember_be5ba072-0fea-468d-9bd4-55710fb7bd25" xlink:to="loc_iaci_DotdashMeredithTermLoanBFacilityMember_f032b087-f253-4e16-aafb-3f07755d36dd" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithRevolvingFacilityMember_9932115b-a953-4b76-bbcc-72606ae63892" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithRevolvingFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_DotdashMeredithCreditAgreementMember_be5ba072-0fea-468d-9bd4-55710fb7bd25" xlink:to="loc_iaci_DotdashMeredithRevolvingFacilityMember_9932115b-a953-4b76-bbcc-72606ae63892" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ANGI3875SeniorNotesMember_36565e93-1c24-460a-b1e4-d3b7f69f7ee5" xlink:href="iaci-20230331.xsd#iaci_ANGI3875SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f31341a-66b5-4c6b-873d-72d424137037" xlink:to="loc_iaci_ANGI3875SeniorNotesMember_36565e93-1c24-460a-b1e4-d3b7f69f7ee5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_9b711c60-47e2-4466-9983-6d4f9187be59" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_9b711c60-47e2-4466-9983-6d4f9187be59" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_9b711c60-47e2-4466-9983-6d4f9187be59_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9b711c60-47e2-4466-9983-6d4f9187be59" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_9b711c60-47e2-4466-9983-6d4f9187be59_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_d208e461-92c5-4b52-a8a3-79292d8a18cb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_9b711c60-47e2-4466-9983-6d4f9187be59" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_d208e461-92c5-4b52-a8a3-79292d8a18cb" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansPayableMember_92bb9305-eb9d-46de-a800-38d4fc12d0c9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LoansPayableMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_d208e461-92c5-4b52-a8a3-79292d8a18cb" xlink:to="loc_us-gaap_LoansPayableMember_92bb9305-eb9d-46de-a800-38d4fc12d0c9" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_0f0c74f5-dbaa-46a6-a4c7-27e21065a37d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SeniorNotesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_d208e461-92c5-4b52-a8a3-79292d8a18cb" xlink:to="loc_us-gaap_SeniorNotesMember_0f0c74f5-dbaa-46a6-a4c7-27e21065a37d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_8663d265-5d17-4595-9d59-e4d2d1669081" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_CreditFacilityAxis_8663d265-5d17-4595-9d59-e4d2d1669081" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_8663d265-5d17-4595-9d59-e4d2d1669081_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_8663d265-5d17-4595-9d59-e4d2d1669081" xlink:to="loc_us-gaap_CreditFacilityDomain_8663d265-5d17-4595-9d59-e4d2d1669081_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_e07c29aa-c22f-491d-b3f7-f6d1e1c3cd25" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_8663d265-5d17-4595-9d59-e4d2d1669081" xlink:to="loc_us-gaap_CreditFacilityDomain_e07c29aa-c22f-491d-b3f7-f6d1e1c3cd25" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_f3b42d43-d1c2-401f-b351-851acd80b9d8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_e07c29aa-c22f-491d-b3f7-f6d1e1c3cd25" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_f3b42d43-d1c2-401f-b351-851acd80b9d8" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_d35f0c9c-0666-4703-997c-9d37624042ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_VariableRateAxis_d35f0c9c-0666-4703-997c-9d37624042ae" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_d35f0c9c-0666-4703-997c-9d37624042ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_d35f0c9c-0666-4703-997c-9d37624042ae" xlink:to="loc_us-gaap_VariableRateDomain_d35f0c9c-0666-4703-997c-9d37624042ae_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_c9957560-a53e-4a8c-88f9-cca1672e98e5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_d35f0c9c-0666-4703-997c-9d37624042ae" xlink:to="loc_us-gaap_VariableRateDomain_c9957560-a53e-4a8c-88f9-cca1672e98e5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_64b1a2e9-3ea6-4bc9-83f2-6e9d4e79098b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_c9957560-a53e-4a8c-88f9-cca1672e98e5" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_64b1a2e9-3ea6-4bc9-83f2-6e9d4e79098b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_f8341b1e-b64e-481c-9eec-5d784d58bca5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BaseRateMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_c9957560-a53e-4a8c-88f9-cca1672e98e5" xlink:to="loc_us-gaap_BaseRateMember_f8341b1e-b64e-481c-9eec-5d784d58bca5" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_c0854059-f3bc-4a3a-9ed8-4628e1ec9621" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_srt_RangeAxis_c0854059-f3bc-4a3a-9ed8-4628e1ec9621" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c0854059-f3bc-4a3a-9ed8-4628e1ec9621_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_c0854059-f3bc-4a3a-9ed8-4628e1ec9621" xlink:to="loc_srt_RangeMember_c0854059-f3bc-4a3a-9ed8-4628e1ec9621_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_567d2a66-0e40-4ed8-bfe1-ad6745767107" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_c0854059-f3bc-4a3a-9ed8-4628e1ec9621" xlink:to="loc_srt_RangeMember_567d2a66-0e40-4ed8-bfe1-ad6745767107" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_93b1e7ea-ad28-458d-84f8-1c42024c7ee5" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_567d2a66-0e40-4ed8-bfe1-ad6745767107" xlink:to="loc_srt_MinimumMember_93b1e7ea-ad28-458d-84f8-1c42024c7ee5" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_9f5925b6-0b55-48ec-99e3-97bd58d3d739" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementScenarioAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_srt_StatementScenarioAxis_9f5925b6-0b55-48ec-99e3-97bd58d3d739" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_9f5925b6-0b55-48ec-99e3-97bd58d3d739_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScenarioUnspecifiedDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_9f5925b6-0b55-48ec-99e3-97bd58d3d739" xlink:to="loc_srt_ScenarioUnspecifiedDomain_9f5925b6-0b55-48ec-99e3-97bd58d3d739_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_8cf0331e-54f5-445e-a3e1-f1d5e05cbd2b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScenarioUnspecifiedDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_9f5925b6-0b55-48ec-99e3-97bd58d3d739" xlink:to="loc_srt_ScenarioUnspecifiedDomain_8cf0331e-54f5-445e-a3e1-f1d5e05cbd2b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_bed7849e-0fa8-4ffc-89eb-eae546bcba80" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScenarioForecastMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_8cf0331e-54f5-445e-a3e1-f1d5e05cbd2b" xlink:to="loc_srt_ScenarioForecastMember_bed7849e-0fa8-4ffc-89eb-eae546bcba80" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_042a10d8-b54d-4126-b3bc-161a35c1eaf2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_042a10d8-b54d-4126-b3bc-161a35c1eaf2" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_042a10d8-b54d-4126-b3bc-161a35c1eaf2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_042a10d8-b54d-4126-b3bc-161a35c1eaf2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_042a10d8-b54d-4126-b3bc-161a35c1eaf2_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_c99f69be-3bc1-4f36-b7e8-ddc58a911307" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_042a10d8-b54d-4126-b3bc-161a35c1eaf2" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_c99f69be-3bc1-4f36-b7e8-ddc58a911307" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_05e026b6-a848-4cbb-8b70-35c70d2476b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_c99f69be-3bc1-4f36-b7e8-ddc58a911307" xlink:to="loc_us-gaap_InterestRateSwapMember_05e026b6-a848-4cbb-8b70-35c70d2476b6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_9f315398-3028-46cb-ab41-20600453c03b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e4d0e81b-a916-4ce1-8349-9cfb09b87d68" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_9f315398-3028-46cb-ab41-20600453c03b" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9f315398-3028-46cb-ab41-20600453c03b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9f315398-3028-46cb-ab41-20600453c03b" xlink:to="loc_us-gaap_SegmentDomain_9f315398-3028-46cb-ab41-20600453c03b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ebba227c-f406-4e49-a93b-051e4331324d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9f315398-3028-46cb-ab41-20600453c03b" xlink:to="loc_us-gaap_SegmentDomain_ebba227c-f406-4e49-a93b-051e4331324d" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_8887c46f-3e35-4692-8b98-9cf84302341c" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ebba227c-f406-4e49-a93b-051e4331324d" xlink:to="loc_iaci_DotdashMeredithMember_8887c46f-3e35-4692-8b98-9cf84302341c" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEDetails" xlink:type="extended" id="i52ea30d9285f4c018f76d7abff15474b_ACCUMULATEDOTHERCOMPREHENSIVELOSSINCOMEDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7520af80-2e90-48aa-8808-f0395cfc8aa8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_8a620425-f15d-42af-adc1-b99a0bb8a626" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7520af80-2e90-48aa-8808-f0395cfc8aa8" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_8a620425-f15d-42af-adc1-b99a0bb8a626" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_36fff29b-8bf8-47fb-be4e-5d27eaa08e27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_8a620425-f15d-42af-adc1-b99a0bb8a626" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_36fff29b-8bf8-47fb-be4e-5d27eaa08e27" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_bfb54676-05a4-4f72-921e-c9e6282cc3ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_8a620425-f15d-42af-adc1-b99a0bb8a626" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_bfb54676-05a4-4f72-921e-c9e6282cc3ea" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8248161e-d4b2-4f7e-a327-70874a12d175" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_8a620425-f15d-42af-adc1-b99a0bb8a626" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_8248161e-d4b2-4f7e-a327-70874a12d175" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_0ac3ded7-5c3b-40f3-a425-d0c625173bf9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociTaxAttributableToParent_e3003f22-9e9e-4634-a302-6a23e845299b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AociTaxAttributableToParent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7520af80-2e90-48aa-8808-f0395cfc8aa8" xlink:to="loc_us-gaap_AociTaxAttributableToParent_e3003f22-9e9e-4634-a302-6a23e845299b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c5929b0b-feef-4755-94ea-7ce7193d699d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_7520af80-2e90-48aa-8808-f0395cfc8aa8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c5929b0b-feef-4755-94ea-7ce7193d699d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_c5929b0b-feef-4755-94ea-7ce7193d699d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab" xlink:to="loc_us-gaap_EquityComponentDomain_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3c1c4728-9f7b-4fe6-a155-c5642e4f97ab" xlink:to="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_4b0c522b-994a-41bc-90ed-0c324e951268" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_4b0c522b-994a-41bc-90ed-0c324e951268" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedForeignCurrencyAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_b31386e2-da63-427c-a372-a192e45916ff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedForeignCurrencyAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedTranslationAdjustmentMember_4b0c522b-994a-41bc-90ed-0c324e951268" xlink:to="loc_us-gaap_AccumulatedForeignCurrencyAdjustmentIncludingPortionAttributableToNoncontrollingInterestMember_b31386e2-da63-427c-a372-a192e45916ff" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember_504d0435-b184-4cc7-8b82-936107a704c1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedTranslationAdjustmentMember_4b0c522b-994a-41bc-90ed-0c324e951268" xlink:to="loc_us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember_504d0435-b184-4cc7-8b82-936107a704c1" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_59d3ea7b-7a68-4f8b-90b9-b75b99cc8cde" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:to="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_59d3ea7b-7a68-4f8b-90b9-b75b99cc8cde" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember_78764f90-2b7c-4e25-b82d-80a181ae2350" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_59d3ea7b-7a68-4f8b-90b9-b75b99cc8cde" xlink:to="loc_us-gaap_AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember_78764f90-2b7c-4e25-b82d-80a181ae2350" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetInvestmentGainLossAttributableToNoncontrollingInterestMember_dd4fe800-f0c9-40c4-b162-df16b724fbff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedNetInvestmentGainLossAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember_59d3ea7b-7a68-4f8b-90b9-b75b99cc8cde" xlink:to="loc_us-gaap_AccumulatedNetInvestmentGainLossAttributableToNoncontrollingInterestMember_dd4fe800-f0c9-40c4-b162-df16b724fbff" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_d799397e-dc42-4211-bac5-c73c04f0adcc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_d799397e-dc42-4211-bac5-c73c04f0adcc" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_3dfb444b-fa90-44cf-b9a4-c3b492bebca9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_d799397e-dc42-4211-bac5-c73c04f0adcc" xlink:to="loc_us-gaap_AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember_3dfb444b-fa90-44cf-b9a4-c3b492bebca9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_4166be75-087b-410c-9e6c-b0d9bdc79a61" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_d799397e-dc42-4211-bac5-c73c04f0adcc" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_4166be75-087b-410c-9e6c-b0d9bdc79a61" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e2694d18-c57b-435d-961c-3545c8ed603d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_ef302c18-e1bd-4619-ad56-9c0ba271ddb9" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e2694d18-c57b-435d-961c-3545c8ed603d" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_6e9ce53e-c7a3-4e5f-a5e0-6b8172408ca7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e2694d18-c57b-435d-961c-3545c8ed603d" xlink:to="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestMember_6e9ce53e-c7a3-4e5f-a5e0-6b8172408ca7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociAttributableToNoncontrollingInterestMember_5c358084-8295-4acf-b826-df76e0f791dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AociAttributableToNoncontrollingInterestMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e2694d18-c57b-435d-961c-3545c8ed603d" xlink:to="loc_us-gaap_AociAttributableToNoncontrollingInterestMember_5c358084-8295-4acf-b826-df76e0f791dc" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SEGMENTINFORMATIONRevenuebyReportableSegmentDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SEGMENTINFORMATIONRevenuebyReportableSegmentDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SEGMENTINFORMATIONRevenuebyReportableSegmentDetails" xlink:type="extended" id="i266d0956565541c3a2d6c9709520e3c7_SEGMENTINFORMATIONRevenuebyReportableSegmentDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_6aca2417-dd23-4763-ae7f-9a35b5ad6870" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_eb547565-8661-4365-a3e7-3fb82cdc43ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6aca2417-dd23-4763-ae7f-9a35b5ad6870" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_eb547565-8661-4365-a3e7-3fb82cdc43ad" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_6aca2417-dd23-4763-ae7f-9a35b5ad6870" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:to="loc_srt_ConsolidationItemsAxis_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b" xlink:to="loc_srt_ConsolidationItemsDomain_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_2d3f2ed0-4d75-4e0a-9c80-4e4a2b77512b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_e2c2cbec-2fee-457f-a3e7-1a0b86c3d26b" xlink:to="loc_srt_ConsolidationItemsDomain_2d3f2ed0-4d75-4e0a-9c80-4e4a2b77512b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_75963b24-d3c7-4b60-af02-4b5dd21416e4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2d3f2ed0-4d75-4e0a-9c80-4e4a2b77512b" xlink:to="loc_us-gaap_OperatingSegmentsMember_75963b24-d3c7-4b60-af02-4b5dd21416e4" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_20715efc-746d-4bcf-a368-96956ef29fc7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntersegmentEliminationMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_2d3f2ed0-4d75-4e0a-9c80-4e4a2b77512b" xlink:to="loc_us-gaap_IntersegmentEliminationMember_20715efc-746d-4bcf-a368-96956ef29fc7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_89903984-433d-4c8b-b51e-00e597fec109" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_89903984-433d-4c8b-b51e-00e597fec109" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_89903984-433d-4c8b-b51e-00e597fec109_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_89903984-433d-4c8b-b51e-00e597fec109" xlink:to="loc_us-gaap_SegmentDomain_89903984-433d-4c8b-b51e-00e597fec109_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_89903984-433d-4c8b-b51e-00e597fec109" xlink:to="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_5c696ce9-1146-49cb-a409-125af52737d6" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:to="loc_iaci_DotdashMeredithMember_5c696ce9-1146-49cb-a409-125af52737d6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_ea3b7054-9511-4d3f-aeef-1ebb387d68d3" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:to="loc_iaci_AngiIncMember_ea3b7054-9511-4d3f-aeef-1ebb387d68d3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SearchMember_f66bf8eb-4d29-4969-a281-9042a33876d0" xlink:href="iaci-20230331.xsd#iaci_SearchMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:to="loc_iaci_SearchMember_f66bf8eb-4d29-4969-a281-9042a33876d0" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EmergingOtherMember_0ac84a0d-5e5f-4b12-8de9-bc2ccfb3ac76" xlink:href="iaci-20230331.xsd#iaci_EmergingOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5d73178f-37ac-4780-bc62-28b80dad6138" xlink:to="loc_iaci_EmergingOtherMember_0ac84a0d-5e5f-4b12-8de9-bc2ccfb3ac76" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_538d2a49-4461-42ce-ae5a-3b0a136a18ff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:to="loc_us-gaap_SubsegmentsAxis_538d2a49-4461-42ce-ae5a-3b0a136a18ff" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_538d2a49-4461-42ce-ae5a-3b0a136a18ff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_538d2a49-4461-42ce-ae5a-3b0a136a18ff" xlink:to="loc_us-gaap_SubsegmentsDomain_538d2a49-4461-42ce-ae5a-3b0a136a18ff_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_538d2a49-4461-42ce-ae5a-3b0a136a18ff" xlink:to="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DigitalMember_e5ca1627-d2ea-4b3c-b521-248be8db3390" xlink:href="iaci-20230331.xsd#iaci_DigitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_DigitalMember_e5ca1627-d2ea-4b3c-b521-248be8db3390" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PrintMember_e6925e83-52e5-4e02-b116-b823056f4d9b" xlink:href="iaci-20230331.xsd#iaci_PrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_PrintMember_e6925e83-52e5-4e02-b116-b823056f4d9b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsSegmentMember_8b3b39f2-dbab-49c7-b217-6799badd36ce" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_AdsAndLeadsSegmentMember_8b3b39f2-dbab-49c7-b217-6799badd36ce" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServicesSegmentMember_33a40914-4a7d-433b-98ef-5d3301d50b16" xlink:href="iaci-20230331.xsd#iaci_ServicesSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_ServicesSegmentMember_33a40914-4a7d-433b-98ef-5d3301d50b16" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RoofingSegmentMember_b7f38c2a-541f-448f-ae83-f777cf9a7fca" xlink:href="iaci-20230331.xsd#iaci_RoofingSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_RoofingSegmentMember_b7f38c2a-541f-448f-ae83-f777cf9a7fca" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_InternationalSegmentMember_d80f1fb6-013a-4d89-85b1-e283268b8f17" xlink:href="iaci-20230331.xsd#iaci_InternationalSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_1d21974a-d0fe-4dbf-80a1-19cab4afcc24" xlink:to="loc_iaci_InternationalSegmentMember_d80f1fb6-013a-4d89-85b1-e283268b8f17" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_76ece9c0-037b-4b5b-a7a4-7c48b792c651" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_38564e59-6619-486f-adf3-5a0c415c9742" xlink:to="loc_srt_StatementGeographicalAxis_76ece9c0-037b-4b5b-a7a4-7c48b792c651" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_76ece9c0-037b-4b5b-a7a4-7c48b792c651_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_76ece9c0-037b-4b5b-a7a4-7c48b792c651" xlink:to="loc_srt_SegmentGeographicalDomain_76ece9c0-037b-4b5b-a7a4-7c48b792c651_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_0ff97e6a-5553-42ff-9098-1b075c64e6a1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_76ece9c0-037b-4b5b-a7a4-7c48b792c651" xlink:to="loc_srt_SegmentGeographicalDomain_0ff97e6a-5553-42ff-9098-1b075c64e6a1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_4c8cc8a4-2633-49ba-a9b3-cfa1a9952b37" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_0ff97e6a-5553-42ff-9098-1b075c64e6a1" xlink:to="loc_country_US_4c8cc8a4-2633-49ba-a9b3-cfa1a9952b37" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SEGMENTINFORMATIONRevenueDisaggregatedbyServiceDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SEGMENTINFORMATIONRevenueDisaggregatedbyServiceDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SEGMENTINFORMATIONRevenueDisaggregatedbyServiceDetails" xlink:type="extended" id="i3a6c663822c341909705ed81b8a10520_SEGMENTINFORMATIONRevenueDisaggregatedbyServiceDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_69d58db7-d074-44d7-b9b5-10bb93db617a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2964844c-d0f9-46b3-bd47-d2179bccd971" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_69d58db7-d074-44d7-b9b5-10bb93db617a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_2964844c-d0f9-46b3-bd47-d2179bccd971" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_69d58db7-d074-44d7-b9b5-10bb93db617a" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_cb2d659a-221a-4612-88ac-3c649bd9c133" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:to="loc_srt_ProductOrServiceAxis_cb2d659a-221a-4612-88ac-3c649bd9c133" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_cb2d659a-221a-4612-88ac-3c649bd9c133_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_cb2d659a-221a-4612-88ac-3c649bd9c133" xlink:to="loc_srt_ProductsAndServicesDomain_cb2d659a-221a-4612-88ac-3c649bd9c133_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_cb2d659a-221a-4612-88ac-3c649bd9c133" xlink:to="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DisplayAdvertisingMember_0445ad67-cace-4630-84cc-a652f3ea88ae" xlink:href="iaci-20230331.xsd#iaci_DisplayAdvertisingMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_DisplayAdvertisingMember_0445ad67-cace-4630-84cc-a652f3ea88ae" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PerformanceMarketingMember_dba7610e-fe2f-41b0-82dd-2a52236af018" xlink:href="iaci-20230331.xsd#iaci_PerformanceMarketingMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_PerformanceMarketingMember_dba7610e-fe2f-41b0-82dd-2a52236af018" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_LicensingAndOtherMember_f8acb58c-8c90-4c26-8dd0-ca59654b7f08" xlink:href="iaci-20230331.xsd#iaci_LicensingAndOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_LicensingAndOtherMember_f8acb58c-8c90-4c26-8dd0-ca59654b7f08" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SubscriptionMember_94f8023f-ef2e-4bad-90f3-b1d1c5db6177" xlink:href="iaci-20230331.xsd#iaci_SubscriptionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_SubscriptionMember_94f8023f-ef2e-4bad-90f3-b1d1c5db6177" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvertisingMember_af01b2e5-73ed-4572-a00d-bd8704dede6e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdvertisingMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_us-gaap_AdvertisingMember_af01b2e5-73ed-4572-a00d-bd8704dede6e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdvertisingGoogleMember_4fadc23d-c421-4799-a1c0-729fc134b293" xlink:href="iaci-20230331.xsd#iaci_AdvertisingGoogleMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdvertisingMember_af01b2e5-73ed-4572-a00d-bd8704dede6e" xlink:to="loc_iaci_AdvertisingGoogleMember_4fadc23d-c421-4799-a1c0-729fc134b293" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdvertisingOtherMember_39c61ba2-6027-43dd-bc24-827e0a3e9c10" xlink:href="iaci-20230331.xsd#iaci_AdvertisingOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdvertisingMember_af01b2e5-73ed-4572-a00d-bd8704dede6e" xlink:to="loc_iaci_AdvertisingOtherMember_39c61ba2-6027-43dd-bc24-827e0a3e9c10" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_NewsstandMember_9197ec94-4610-437b-b085-1a89506097cf" xlink:href="iaci-20230331.xsd#iaci_NewsstandMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_NewsstandMember_9197ec94-4610-437b-b085-1a89506097cf" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ProjectAndOtherPrintMember_f5ef0ec5-54ef-48fa-a387-4367dd7de71a" xlink:href="iaci-20230331.xsd#iaci_ProjectAndOtherPrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_ProjectAndOtherPrintMember_f5ef0ec5-54ef-48fa-a387-4367dd7de71a" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsConsumerConnectionMember_75178527-f71d-4a77-8c53-6180c9b17ef8" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsConsumerConnectionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:to="loc_iaci_AdsAndLeadsConsumerConnectionMember_75178527-f71d-4a77-8c53-6180c9b17ef8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsAdvertisingRevenueMember_8e468988-221a-457a-a203-355eb905ca5e" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsAdvertisingRevenueMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:to="loc_iaci_AdsAndLeadsAdvertisingRevenueMember_8e468988-221a-457a-a203-355eb905ca5e" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsMembershipSubscriptionMember_bf619e3a-01fb-40bf-8e1a-d531c68db94b" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsMembershipSubscriptionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:to="loc_iaci_AdsAndLeadsMembershipSubscriptionMember_bf619e3a-01fb-40bf-8e1a-d531c68db94b" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsOtherMember_13b95990-a213-450e-bc59-d0636654740e" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_iaci_AdsAndLeadsMember_5713f631-5350-43dc-a100-620077b7f58d" xlink:to="loc_iaci_AdsAndLeadsOtherMember_13b95990-a213-450e-bc59-d0636654740e" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServiceProfessionalMembershipSubscriptionRevenueMember_f2cbbdbd-2d64-4edc-93c1-4ec2d9b56840" xlink:href="iaci-20230331.xsd#iaci_ServiceProfessionalMembershipSubscriptionRevenueMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_ServiceProfessionalMembershipSubscriptionRevenueMember_f2cbbdbd-2d64-4edc-93c1-4ec2d9b56840" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdvertisingAndOtherMember_b5d6e509-8cae-4cc1-a99c-b659da7b1599" xlink:href="iaci-20230331.xsd#iaci_AdvertisingAndOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_AdvertisingAndOtherMember_b5d6e509-8cae-4cc1-a99c-b659da7b1599" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductAndServiceOtherMember_0b5648a8-0180-40a8-b3dd-923db944d6a6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductAndServiceOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_us-gaap_ProductAndServiceOtherMember_0b5648a8-0180-40a8-b3dd-923db944d6a6" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServiceSubscriptionMember_c06aa3e5-4d41-4ded-881e-14b3ee18a132" xlink:href="iaci-20230331.xsd#iaci_ServiceSubscriptionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_ServiceSubscriptionMember_c06aa3e5-4d41-4ded-881e-14b3ee18a132" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MarketplaceMember_c4b0438b-ce7f-4769-8486-1ca89d04569d" xlink:href="iaci-20230331.xsd#iaci_MarketplaceMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_MarketplaceMember_c4b0438b-ce7f-4769-8486-1ca89d04569d" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MediaProductionAndDistributionMember_63a2f351-9200-4e5d-9136-745d496a5758" xlink:href="iaci-20230331.xsd#iaci_MediaProductionAndDistributionMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_iaci_MediaProductionAndDistributionMember_63a2f351-9200-4e5d-9136-745d496a5758" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_70ad58b4-19a7-45ca-a269-a9ea1c338fda" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ServiceMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_ae1a9346-43de-4f67-8788-3c1b255a9135" xlink:to="loc_us-gaap_ServiceMember_70ad58b4-19a7-45ca-a269-a9ea1c338fda" xlink:type="arc" order="14"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_89448c19-848a-4ff8-a691-4939e76f1d11" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:to="loc_srt_StatementGeographicalAxis_89448c19-848a-4ff8-a691-4939e76f1d11" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_89448c19-848a-4ff8-a691-4939e76f1d11_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_89448c19-848a-4ff8-a691-4939e76f1d11" xlink:to="loc_srt_SegmentGeographicalDomain_89448c19-848a-4ff8-a691-4939e76f1d11_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_4a8f088b-8a15-498a-9c84-0575f8eb21ce" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_89448c19-848a-4ff8-a691-4939e76f1d11" xlink:to="loc_srt_SegmentGeographicalDomain_4a8f088b-8a15-498a-9c84-0575f8eb21ce" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_05343365-b43b-49c3-9052-2388df10c941" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_4a8f088b-8a15-498a-9c84-0575f8eb21ce" xlink:to="loc_country_US_05343365-b43b-49c3-9052-2388df10c941" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_ad8e72ab-e892-423b-8fe1-61fc5894b99e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonUsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_4a8f088b-8a15-498a-9c84-0575f8eb21ce" xlink:to="loc_us-gaap_NonUsMember_ad8e72ab-e892-423b-8fe1-61fc5894b99e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_0b05a75c-110e-4b00-b6e3-b23410b38731" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:to="loc_srt_ConsolidationItemsAxis_0b05a75c-110e-4b00-b6e3-b23410b38731" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_0b05a75c-110e-4b00-b6e3-b23410b38731_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_0b05a75c-110e-4b00-b6e3-b23410b38731" xlink:to="loc_srt_ConsolidationItemsDomain_0b05a75c-110e-4b00-b6e3-b23410b38731_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_9c9d8c38-0e09-4f69-aa2c-e1c8bed9b60a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_0b05a75c-110e-4b00-b6e3-b23410b38731" xlink:to="loc_srt_ConsolidationItemsDomain_9c9d8c38-0e09-4f69-aa2c-e1c8bed9b60a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_5bf87429-5896-41b2-bc87-d2a93b1c593b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9c9d8c38-0e09-4f69-aa2c-e1c8bed9b60a" xlink:to="loc_us-gaap_OperatingSegmentsMember_5bf87429-5896-41b2-bc87-d2a93b1c593b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_10a6ab55-ac52-4500-8410-26947726536e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntersegmentEliminationMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_9c9d8c38-0e09-4f69-aa2c-e1c8bed9b60a" xlink:to="loc_us-gaap_IntersegmentEliminationMember_10a6ab55-ac52-4500-8410-26947726536e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_028c4cb4-455a-4e7c-8c97-0de3749dbdb6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_028c4cb4-455a-4e7c-8c97-0de3749dbdb6" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_028c4cb4-455a-4e7c-8c97-0de3749dbdb6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_028c4cb4-455a-4e7c-8c97-0de3749dbdb6" xlink:to="loc_us-gaap_SegmentDomain_028c4cb4-455a-4e7c-8c97-0de3749dbdb6_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_028c4cb4-455a-4e7c-8c97-0de3749dbdb6" xlink:to="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_b942e221-bd24-4543-9896-3470f86d5328" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:to="loc_iaci_DotdashMeredithMember_b942e221-bd24-4543-9896-3470f86d5328" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_63d87006-313c-4ddc-af0c-7e9f0d96acb9" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:to="loc_iaci_AngiIncMember_63d87006-313c-4ddc-af0c-7e9f0d96acb9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SearchMember_f7ff5ba4-440c-4771-a4fe-8d59ef76603e" xlink:href="iaci-20230331.xsd#iaci_SearchMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:to="loc_iaci_SearchMember_f7ff5ba4-440c-4771-a4fe-8d59ef76603e" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EmergingOtherMember_d49b6104-a5e5-4ae7-965d-36d08562f5ca" xlink:href="iaci-20230331.xsd#iaci_EmergingOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_dd9cf24f-952d-4d82-8215-efbd9f2bd59c" xlink:to="loc_iaci_EmergingOtherMember_d49b6104-a5e5-4ae7-965d-36d08562f5ca" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_1350a0fb-9612-46f0-ba9c-060bc1ed8a24" xlink:to="loc_us-gaap_SubsegmentsAxis_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5" xlink:to="loc_us-gaap_SubsegmentsDomain_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_ea9f73b1-cb1e-4375-9e94-9f14e853ebd5" xlink:to="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DigitalMember_86dcd56c-8df6-4c0f-be44-62aedb5df4ad" xlink:href="iaci-20230331.xsd#iaci_DigitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:to="loc_iaci_DigitalMember_86dcd56c-8df6-4c0f-be44-62aedb5df4ad" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PrintMember_f1b5e807-c211-4000-a0c3-4e6a28314286" xlink:href="iaci-20230331.xsd#iaci_PrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:to="loc_iaci_PrintMember_f1b5e807-c211-4000-a0c3-4e6a28314286" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServicesSegmentMember_6e53d0b7-3137-4e31-a86c-74f1d4f28ac0" xlink:href="iaci-20230331.xsd#iaci_ServicesSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:to="loc_iaci_ServicesSegmentMember_6e53d0b7-3137-4e31-a86c-74f1d4f28ac0" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RoofingSegmentMember_8ac72d6b-9581-482f-b9c6-7c5a12569100" xlink:href="iaci-20230331.xsd#iaci_RoofingSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_dd900fc9-7f37-4625-8c36-6fc195d31bbd" xlink:to="loc_iaci_RoofingSegmentMember_8ac72d6b-9581-482f-b9c6-7c5a12569100" xlink:type="arc" order="3"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SEGMENTINFORMATIONRevenueandLongLivedAssetsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SEGMENTINFORMATIONRevenueandLongLivedAssetsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SEGMENTINFORMATIONRevenueandLongLivedAssetsDetails" xlink:type="extended" id="i090040bac5c043f29e4e364fa82f3e9c_SEGMENTINFORMATIONRevenueandLongLivedAssetsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_6fdc0e06-1bdf-4dbd-b28e-fe48c2eaa6f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_e9d59071-8035-47e9-a904-01cfa46a7c72" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Revenues"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_6fdc0e06-1bdf-4dbd-b28e-fe48c2eaa6f6" xlink:to="loc_us-gaap_Revenues_e9d59071-8035-47e9-a904-01cfa46a7c72" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_49448216-fa04-448a-86d6-dcce69b25536" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_6fdc0e06-1bdf-4dbd-b28e-fe48c2eaa6f6" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_49448216-fa04-448a-86d6-dcce69b25536" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_dc960884-cd42-47fc-9491-1dc86e6b2d10" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_6fdc0e06-1bdf-4dbd-b28e-fe48c2eaa6f6" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_dc960884-cd42-47fc-9491-1dc86e6b2d10" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_72ba597c-1a52-4800-94db-48fdc18dac47" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_dc960884-cd42-47fc-9491-1dc86e6b2d10" xlink:to="loc_srt_StatementGeographicalAxis_72ba597c-1a52-4800-94db-48fdc18dac47" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_72ba597c-1a52-4800-94db-48fdc18dac47_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_72ba597c-1a52-4800-94db-48fdc18dac47" xlink:to="loc_srt_SegmentGeographicalDomain_72ba597c-1a52-4800-94db-48fdc18dac47_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_825073e9-c21c-4bd6-8753-3567ea5b04dc" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_72ba597c-1a52-4800-94db-48fdc18dac47" xlink:to="loc_srt_SegmentGeographicalDomain_825073e9-c21c-4bd6-8753-3567ea5b04dc" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_164b488b-899d-4bbb-9110-0728bc7cd7b4" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_825073e9-c21c-4bd6-8753-3567ea5b04dc" xlink:to="loc_country_US_164b488b-899d-4bbb-9110-0728bc7cd7b4" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_81b2101b-1fb9-4f18-b402-7fae6549b0db" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonUsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_825073e9-c21c-4bd6-8753-3567ea5b04dc" xlink:to="loc_us-gaap_NonUsMember_81b2101b-1fb9-4f18-b402-7fae6549b0db" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SEGMENTINFORMATIONOperatingLossIncomeandAdjustedEBITDADetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SEGMENTINFORMATIONOperatingLossIncomeandAdjustedEBITDADetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SEGMENTINFORMATIONOperatingLossIncomeandAdjustedEBITDADetails" xlink:type="extended" id="i6ec6605f024442698fcbc87d690884e6_SEGMENTINFORMATIONOperatingLossIncomeandAdjustedEBITDADetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_656b1c95-df35-4826-b0c6-6250b65c17bc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_OperatingIncomeLoss_656b1c95-df35-4826-b0c6-6250b65c17bc" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdjustedEBITDA_bc4d4c86-1be9-4271-aca8-4ee2ce8021e2" xlink:href="iaci-20230331.xsd#iaci_AdjustedEBITDA"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_iaci_AdjustedEBITDA_bc4d4c86-1be9-4271-aca8-4ee2ce8021e2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetImpairmentCharges_da2c3af2-b7ad-4245-b2dd-29289f78784f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetImpairmentCharges"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_AssetImpairmentCharges_da2c3af2-b7ad-4245-b2dd-29289f78784f" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLeasehold_76134695-0f6b-4f7c-b804-a907e306995d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ImpairmentOfLeasehold"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_ImpairmentOfLeasehold_76134695-0f6b-4f7c-b804-a907e306995d" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_c9e38ce7-a126-41d2-a030-ddcb1a7b2cd7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestructuringCharges"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_RestructuringCharges_c9e38ce7-a126-41d2-a030-ddcb1a7b2cd7" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1db21e40-f7da-4a6d-a077-c83e6bcfe172" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_1db21e40-f7da-4a6d-a077-c83e6bcfe172" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseImpairmentLoss_a1af7f14-e113-49e1-8060-a42f583471a3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingLeaseImpairmentLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_OperatingLeaseImpairmentLoss_a1af7f14-e113-49e1-8060-a42f583471a3" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_d5d4ad35-8b7c-4afe-9930-5695639bfe8d" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:to="loc_srt_ConsolidationItemsAxis_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a" xlink:to="loc_srt_ConsolidationItemsDomain_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_e852a731-bf15-41bd-95c2-6ab599dc6970" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_7bbfeb6b-c8fb-4205-bfcd-38f88fa57d4a" xlink:to="loc_srt_ConsolidationItemsDomain_e852a731-bf15-41bd-95c2-6ab599dc6970" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_cfb77a92-4e07-4a76-8cfa-669ef9b6a11e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e852a731-bf15-41bd-95c2-6ab599dc6970" xlink:to="loc_us-gaap_OperatingSegmentsMember_cfb77a92-4e07-4a76-8cfa-669ef9b6a11e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_b24da06a-824a-4875-abf1-f6e17830b9ac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CorporateNonSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_e852a731-bf15-41bd-95c2-6ab599dc6970" xlink:to="loc_us-gaap_CorporateNonSegmentMember_b24da06a-824a-4875-abf1-f6e17830b9ac" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_fbf58c87-83e5-4730-bf43-2fb11a3721c0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_fbf58c87-83e5-4730-bf43-2fb11a3721c0" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_fbf58c87-83e5-4730-bf43-2fb11a3721c0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_fbf58c87-83e5-4730-bf43-2fb11a3721c0" xlink:to="loc_us-gaap_SegmentDomain_fbf58c87-83e5-4730-bf43-2fb11a3721c0_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_fbf58c87-83e5-4730-bf43-2fb11a3721c0" xlink:to="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_6726bf99-9c71-4918-a931-3ebebabc8ab7" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:to="loc_iaci_DotdashMeredithMember_6726bf99-9c71-4918-a931-3ebebabc8ab7" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_91d29640-2f9f-42ab-bf7e-0f55fc627530" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:to="loc_iaci_AngiIncMember_91d29640-2f9f-42ab-bf7e-0f55fc627530" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SearchMember_2043125a-4772-42a1-9ed9-0ac14bfd21d8" xlink:href="iaci-20230331.xsd#iaci_SearchMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:to="loc_iaci_SearchMember_2043125a-4772-42a1-9ed9-0ac14bfd21d8" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EmergingOtherMember_b38208ae-4471-40a2-813a-f76e21c304eb" xlink:href="iaci-20230331.xsd#iaci_EmergingOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_9d533dc6-3bc2-4e1b-a2e6-6d57fe419029" xlink:to="loc_iaci_EmergingOtherMember_b38208ae-4471-40a2-813a-f76e21c304eb" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_c551444a-67c9-43cd-979d-84f10b142ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:to="loc_us-gaap_SubsegmentsAxis_c551444a-67c9-43cd-979d-84f10b142ea8" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_c551444a-67c9-43cd-979d-84f10b142ea8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_c551444a-67c9-43cd-979d-84f10b142ea8" xlink:to="loc_us-gaap_SubsegmentsDomain_c551444a-67c9-43cd-979d-84f10b142ea8_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_75a72a28-2769-40d8-8106-67146e3e10b1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_c551444a-67c9-43cd-979d-84f10b142ea8" xlink:to="loc_us-gaap_SubsegmentsDomain_75a72a28-2769-40d8-8106-67146e3e10b1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DigitalMember_cabcc9e2-553e-44df-a6c1-39fa8414f73b" xlink:href="iaci-20230331.xsd#iaci_DigitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_75a72a28-2769-40d8-8106-67146e3e10b1" xlink:to="loc_iaci_DigitalMember_cabcc9e2-553e-44df-a6c1-39fa8414f73b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PrintMember_b42ace21-2aa7-4e94-8f61-115d558c4865" xlink:href="iaci-20230331.xsd#iaci_PrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_75a72a28-2769-40d8-8106-67146e3e10b1" xlink:to="loc_iaci_PrintMember_b42ace21-2aa7-4e94-8f61-115d558c4865" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SubsegmentOtherMember_2c73538a-2151-4ba7-a6c9-9f6ffb4b2aa8" xlink:href="iaci-20230331.xsd#iaci_SubsegmentOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_75a72a28-2769-40d8-8106-67146e3e10b1" xlink:to="loc_iaci_SubsegmentOtherMember_2c73538a-2151-4ba7-a6c9-9f6ffb4b2aa8" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_67770a7d-531b-414e-8e32-274abfce2d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_ee8a32dc-b045-477a-867c-f49fa4294b39" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_67770a7d-531b-414e-8e32-274abfce2d2a" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67770a7d-531b-414e-8e32-274abfce2d2a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_67770a7d-531b-414e-8e32-274abfce2d2a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_67770a7d-531b-414e-8e32-274abfce2d2a_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2363deff-439e-48f5-bc2b-31103e95dc07" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_67770a7d-531b-414e-8e32-274abfce2d2a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2363deff-439e-48f5-bc2b-31103e95dc07" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_MeredithCorporationMember_593829ba-634a-479e-96d3-30be7e7277f6" xlink:href="iaci-20230331.xsd#iaci_MeredithCorporationMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_2363deff-439e-48f5-bc2b-31103e95dc07" xlink:to="loc_iaci_MeredithCorporationMember_593829ba-634a-479e-96d3-30be7e7277f6" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoOperatingIncomeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoOperatingIncomeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoOperatingIncomeDetails" xlink:type="extended" id="i36a7116d7fc94f1383faa11564f686c0_SEGMENTINFORMATIONReconciliationofAdjustedEBITDAtoOperatingIncomeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_d69469cd-7956-452d-a2c8-a4975f457fbf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_OperatingIncomeLoss_d69469cd-7956-452d-a2c8-a4975f457fbf" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_dd1620ba-a39e-4bbb-bee6-c424847fe6a4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_dd1620ba-a39e-4bbb-bee6-c424847fe6a4" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_768cd3ad-7040-43d1-b16f-b086538cb804" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Depreciation"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_Depreciation_768cd3ad-7040-43d1-b16f-b086538cb804" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_5bc4ec50-511c-4583-872e-719703e500fe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_5bc4ec50-511c-4583-872e-719703e500fe" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_e1430995-9274-4cab-a105-e6e0f744ef3c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_e1430995-9274-4cab-a105-e6e0f744ef3c" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdjustedEBITDA_af129fe0-94d3-4d3b-9d85-f5dd6d90f91a" xlink:href="iaci-20230331.xsd#iaci_AdjustedEBITDA"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_iaci_AdjustedEBITDA_af129fe0-94d3-4d3b-9d85-f5dd6d90f91a" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_e364088e-c79c-46d6-ac80-087f8185b4e9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_InterestExpense_e364088e-c79c-46d6-ac80-087f8185b4e9" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_9eefbd64-ae83-46b3-aa9d-714e4fcefc57" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_9eefbd64-ae83-46b3-aa9d-714e4fcefc57" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_71fb8b0d-66fe-4ec8-b313-39bd774873e1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_71fb8b0d-66fe-4ec8-b313-39bd774873e1" xlink:type="arc" order="8"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_69a277b4-e035-469f-a73b-8a95f61fc3e1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_69a277b4-e035-469f-a73b-8a95f61fc3e1" xlink:type="arc" order="9"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_baec8390-2017-4db2-aa04-741ee66e04a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_baec8390-2017-4db2-aa04-741ee66e04a7" xlink:type="arc" order="10"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_6177639d-0f2d-4423-b2e3-6bb8d54e6562" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_ProfitLoss_6177639d-0f2d-4423-b2e3-6bb8d54e6562" xlink:type="arc" order="11"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_2eb9fe6c-7078-418e-adfb-4c90bb6f8b10" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_2eb9fe6c-7078-418e-adfb-4c90bb6f8b10" xlink:type="arc" order="12"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_d3b0f2bb-09c5-47f9-a33b-0508341c8bad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_NetIncomeLoss_d3b0f2bb-09c5-47f9-a33b-0508341c8bad" xlink:type="arc" order="13"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable_7c5f5c90-44f4-4181-8892-edb259399c47" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingOtherSignificantReconcilingItemLineItems_e913579f-e7b1-405f-86c1-75b5091ae4aa" xlink:to="loc_us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable_7c5f5c90-44f4-4181-8892-edb259399c47" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_5dc2de99-581f-42ed-9167-780a5bcdaf41" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable_7c5f5c90-44f4-4181-8892-edb259399c47" xlink:to="loc_srt_ConsolidationItemsAxis_5dc2de99-581f-42ed-9167-780a5bcdaf41" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_5dc2de99-581f-42ed-9167-780a5bcdaf41_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_5dc2de99-581f-42ed-9167-780a5bcdaf41" xlink:to="loc_srt_ConsolidationItemsDomain_5dc2de99-581f-42ed-9167-780a5bcdaf41_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_3b2d0832-5cc7-4fef-9e0e-14e78a29636f" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_5dc2de99-581f-42ed-9167-780a5bcdaf41" xlink:to="loc_srt_ConsolidationItemsDomain_3b2d0832-5cc7-4fef-9e0e-14e78a29636f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_11858a55-bab3-4ac6-9f28-18d29e9846f5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3b2d0832-5cc7-4fef-9e0e-14e78a29636f" xlink:to="loc_us-gaap_OperatingSegmentsMember_11858a55-bab3-4ac6-9f28-18d29e9846f5" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_292cb222-d4ec-4e14-a620-49526d8c09b1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CorporateNonSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_3b2d0832-5cc7-4fef-9e0e-14e78a29636f" xlink:to="loc_us-gaap_CorporateNonSegmentMember_292cb222-d4ec-4e14-a620-49526d8c09b1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable_7c5f5c90-44f4-4181-8892-edb259399c47" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6" xlink:to="loc_us-gaap_SegmentDomain_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_0a453ddb-5e84-47c2-ba8c-8d5d500cb6b6" xlink:to="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DotdashMeredithMember_266deeec-9977-4b86-a536-75ef7568aad3" xlink:href="iaci-20230331.xsd#iaci_DotdashMeredithMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:to="loc_iaci_DotdashMeredithMember_266deeec-9977-4b86-a536-75ef7568aad3" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AngiIncMember_764ea7e4-d95d-4d21-89f1-72e090fe24d3" xlink:href="iaci-20230331.xsd#iaci_AngiIncMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:to="loc_iaci_AngiIncMember_764ea7e4-d95d-4d21-89f1-72e090fe24d3" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SearchMember_8f8a8242-ca0b-4385-a4ef-9bddd4bdcf24" xlink:href="iaci-20230331.xsd#iaci_SearchMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:to="loc_iaci_SearchMember_8f8a8242-ca0b-4385-a4ef-9bddd4bdcf24" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_EmergingOtherMember_8a40c1b8-09b2-4439-ad6e-c2c7ceb5192d" xlink:href="iaci-20230331.xsd#iaci_EmergingOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_153ebf5d-1637-4782-9a46-7266121a35f9" xlink:to="loc_iaci_EmergingOtherMember_8a40c1b8-09b2-4439-ad6e-c2c7ceb5192d" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_6e05c13c-76fa-4891-9c8b-17627456aa94" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOtherSignificantReconcilingItemsFromSegmentsToConsolidatedTable_7c5f5c90-44f4-4181-8892-edb259399c47" xlink:to="loc_us-gaap_SubsegmentsAxis_6e05c13c-76fa-4891-9c8b-17627456aa94" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_6e05c13c-76fa-4891-9c8b-17627456aa94_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_6e05c13c-76fa-4891-9c8b-17627456aa94" xlink:to="loc_us-gaap_SubsegmentsDomain_6e05c13c-76fa-4891-9c8b-17627456aa94_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsegmentsDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_6e05c13c-76fa-4891-9c8b-17627456aa94" xlink:to="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_DigitalMember_d59ac99e-0027-4e14-911c-05b9b7ec4a34" xlink:href="iaci-20230331.xsd#iaci_DigitalMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_DigitalMember_d59ac99e-0027-4e14-911c-05b9b7ec4a34" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PrintMember_146b82d1-e5f9-4175-b99a-158f9b2179e7" xlink:href="iaci-20230331.xsd#iaci_PrintMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_PrintMember_146b82d1-e5f9-4175-b99a-158f9b2179e7" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_SubsegmentOtherMember_d7bf3c81-3276-47d1-9d35-2cf2efa43e3a" xlink:href="iaci-20230331.xsd#iaci_SubsegmentOtherMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_SubsegmentOtherMember_d7bf3c81-3276-47d1-9d35-2cf2efa43e3a" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_AdsAndLeadsSegmentMember_88e1a378-064a-4eb5-aa41-8651a7c91f67" xlink:href="iaci-20230331.xsd#iaci_AdsAndLeadsSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_AdsAndLeadsSegmentMember_88e1a378-064a-4eb5-aa41-8651a7c91f67" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_ServicesSegmentMember_9b38d7e9-8621-4fe4-8c7f-8633011b7f20" xlink:href="iaci-20230331.xsd#iaci_ServicesSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_ServicesSegmentMember_9b38d7e9-8621-4fe4-8c7f-8633011b7f20" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RoofingSegmentMember_2ab2c46d-0ea5-4e05-8914-18b6f31517d4" xlink:href="iaci-20230331.xsd#iaci_RoofingSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_RoofingSegmentMember_2ab2c46d-0ea5-4e05-8914-18b6f31517d4" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_InternationalSegmentMember_488cc0ac-7cf5-4c01-8849-61b4c908af6d" xlink:href="iaci-20230331.xsd#iaci_InternationalSegmentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_4dd7e390-a0e0-43c5-bc81-90aed479c851" xlink:to="loc_iaci_InternationalSegmentMember_488cc0ac-7cf5-4c01-8849-61b4c908af6d" xlink:type="arc" order="6"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#PENSIONANDPOSTRETIREMENTBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="extended" id="idae8662734b54ae4a269997f991c6b95_PENSIONANDPOSTRETIREMENTBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_a6abe514-1906-442c-919b-08efa00fced9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_a6abe514-1906-442c-919b-08efa00fced9" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_262e71e1-9374-4eed-870d-6e9c4af70bec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_262e71e1-9374-4eed-870d-6e9c4af70bec" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_8812aee1-0535-4a54-8be3-4324c5dc0a44" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_8812aee1-0535-4a54-8be3-4324c5dc0a44" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_0048bdd5-3a87-4183-8a65-748d7d0379e8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_0048bdd5-3a87-4183-8a65-748d7d0379e8" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9117e8ad-deee-425b-bdf6-be07d564bcc3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_9117e8ad-deee-425b-bdf6-be07d564bcc3" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_5d115946-8588-4181-aeff-763addb7896e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0cb07c92-6bbd-4709-b10e-afc051269e68" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_5d115946-8588-4181-aeff-763addb7896e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_8183bc35-4ced-42b7-a7ee-646541624f2e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_5d115946-8588-4181-aeff-763addb7896e" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_8183bc35-4ced-42b7-a7ee-646541624f2e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_8183bc35-4ced-42b7-a7ee-646541624f2e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_8183bc35-4ced-42b7-a7ee-646541624f2e" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_8183bc35-4ced-42b7-a7ee-646541624f2e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_28ab36e1-a8ef-41d1-9af4-b4e933086308" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_8183bc35-4ced-42b7-a7ee-646541624f2e" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_28ab36e1-a8ef-41d1-9af4-b4e933086308" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_9f96758e-6730-4543-b6f1-4bb683c9f093" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_28ab36e1-a8ef-41d1-9af4-b4e933086308" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_9f96758e-6730-4543-b6f1-4bb683c9f093" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_935825c2-e1bd-472f-8ef7-fa3313ba85f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_28ab36e1-a8ef-41d1-9af4-b4e933086308" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_935825c2-e1bd-472f-8ef7-fa3313ba85f6" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_c6e357ef-555a-4743-a237-924096405b0b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_5d115946-8588-4181-aeff-763addb7896e" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_c6e357ef-555a-4743-a237-924096405b0b" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_c6e357ef-555a-4743-a237-924096405b0b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_c6e357ef-555a-4743-a237-924096405b0b" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_c6e357ef-555a-4743-a237-924096405b0b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_6c5e4447-3089-42c6-8356-2cb4538d2612" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_c6e357ef-555a-4743-a237-924096405b0b" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_6c5e4447-3089-42c6-8356-2cb4538d2612" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_ee5d807e-d368-46b1-8d9e-07372581e27d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6c5e4447-3089-42c6-8356-2cb4538d2612" xlink:to="loc_us-gaap_DomesticPlanMember_ee5d807e-d368-46b1-8d9e-07372581e27d" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_06a7bc8e-60fb-49ae-9fe4-7b7b0c2fb73f" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_ee5d807e-d368-46b1-8d9e-07372581e27d" xlink:to="loc_country_US_06a7bc8e-60fb-49ae-9fe4-7b7b0c2fb73f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_eb0ffc3c-a752-4d36-85e1-c567832ef4e3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6c5e4447-3089-42c6-8356-2cb4538d2612" xlink:to="loc_us-gaap_ForeignPlanMember_eb0ffc3c-a752-4d36-85e1-c567832ef4e3" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#PENSIONANDPOSTRETIREMENTBENEFITPLANSNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSNarrativeDetails" xlink:type="extended" id="i17f0fc1243ed4410ba5d12ecc9a537ba_PENSIONANDPOSTRETIREMENTBENEFITPLANSNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_19e4538d-3909-4d68-a4fd-f37e32ce259a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_cbd2a59b-f2d4-4bf4-b008-60892b4b55e6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_19e4538d-3909-4d68-a4fd-f37e32ce259a" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_cbd2a59b-f2d4-4bf4-b008-60892b4b55e6" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3887ea72-2e73-414e-95f9-ac8b43c1bff9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_19e4538d-3909-4d68-a4fd-f37e32ce259a" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3887ea72-2e73-414e-95f9-ac8b43c1bff9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_076c085d-60cb-40db-bdc4-1519ede09132" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3887ea72-2e73-414e-95f9-ac8b43c1bff9" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_076c085d-60cb-40db-bdc4-1519ede09132" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_076c085d-60cb-40db-bdc4-1519ede09132_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_076c085d-60cb-40db-bdc4-1519ede09132" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_076c085d-60cb-40db-bdc4-1519ede09132_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_98fee4bf-d9bb-460d-9962-f71c1515b6f8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_076c085d-60cb-40db-bdc4-1519ede09132" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_98fee4bf-d9bb-460d-9962-f71c1515b6f8" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_32e54170-d4ce-4f96-b2ae-a1ca5ad2a7a1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_98fee4bf-d9bb-460d-9962-f71c1515b6f8" xlink:to="loc_us-gaap_DomesticPlanMember_32e54170-d4ce-4f96-b2ae-a1ca5ad2a7a1" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_8927ec16-c1cc-49f7-a59d-ae7743b9db55" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_32e54170-d4ce-4f96-b2ae-a1ca5ad2a7a1" xlink:to="loc_country_US_8927ec16-c1cc-49f7-a59d-ae7743b9db55" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_27f4eeea-67ca-48ee-9efa-0c366d40fa07" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_98fee4bf-d9bb-460d-9962-f71c1515b6f8" xlink:to="loc_us-gaap_ForeignPlanMember_27f4eeea-67ca-48ee-9efa-0c366d40fa07" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_6e75ce0a-b31d-440e-b11c-d507b2c649a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3887ea72-2e73-414e-95f9-ac8b43c1bff9" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_6e75ce0a-b31d-440e-b11c-d507b2c649a2" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_6e75ce0a-b31d-440e-b11c-d507b2c649a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_6e75ce0a-b31d-440e-b11c-d507b2c649a2" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_6e75ce0a-b31d-440e-b11c-d507b2c649a2_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_3f86b178-9fe6-43eb-ba8b-bdb096fa8170" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_6e75ce0a-b31d-440e-b11c-d507b2c649a2" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_3f86b178-9fe6-43eb-ba8b-bdb096fa8170" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_777c04b7-1f06-4a64-9141-901e714295cf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_3f86b178-9fe6-43eb-ba8b-bdb096fa8170" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_777c04b7-1f06-4a64-9141-901e714295cf" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSExpectedReturnonPlanAssetsDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#PENSIONANDPOSTRETIREMENTBENEFITPLANSExpectedReturnonPlanAssetsDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/PENSIONANDPOSTRETIREMENTBENEFITPLANSExpectedReturnonPlanAssetsDetails" xlink:type="extended" id="if85b64a54653434d9bf89cab3b98d315_PENSIONANDPOSTRETIREMENTBENEFITPLANSExpectedReturnonPlanAssetsDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3e3fc48e-db62-4bdd-be26-cffcb5efadd3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostChangeDueToSubsequentInterimMeasurementWeightedAverageExpectedLongTermRateOfReturnOnPlanAssets_6e4771da-4184-4097-9546-58be433d87b1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostChangeDueToSubsequentInterimMeasurementWeightedAverageExpectedLongTermRateOfReturnOnPlanAssets"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3e3fc48e-db62-4bdd-be26-cffcb5efadd3" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostChangeDueToSubsequentInterimMeasurementWeightedAverageExpectedLongTermRateOfReturnOnPlanAssets_6e4771da-4184-4097-9546-58be433d87b1" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b3d8a4a9-10d6-47a7-b492-f13cccbea673" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3e3fc48e-db62-4bdd-be26-cffcb5efadd3" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b3d8a4a9-10d6-47a7-b492-f13cccbea673" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_707632ea-6144-4f79-9572-8091b5ee8d14" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b3d8a4a9-10d6-47a7-b492-f13cccbea673" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_707632ea-6144-4f79-9572-8091b5ee8d14" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_707632ea-6144-4f79-9572-8091b5ee8d14_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_707632ea-6144-4f79-9572-8091b5ee8d14" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_707632ea-6144-4f79-9572-8091b5ee8d14_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_0ccbde3c-e6a8-4b17-806a-4193ad61a361" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_707632ea-6144-4f79-9572-8091b5ee8d14" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_0ccbde3c-e6a8-4b17-806a-4193ad61a361" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_d8091653-5bb8-46e7-bfcb-3593c2e4430a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_0ccbde3c-e6a8-4b17-806a-4193ad61a361" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_d8091653-5bb8-46e7-bfcb-3593c2e4430a" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_e30c5600-e83a-411c-9c5d-79623b445c25" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b3d8a4a9-10d6-47a7-b492-f13cccbea673" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_e30c5600-e83a-411c-9c5d-79623b445c25" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e30c5600-e83a-411c-9c5d-79623b445c25_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_e30c5600-e83a-411c-9c5d-79623b445c25" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e30c5600-e83a-411c-9c5d-79623b445c25_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_296c57d0-f2fb-4735-9940-daf5ae308ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_e30c5600-e83a-411c-9c5d-79623b445c25" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_296c57d0-f2fb-4735-9940-daf5ae308ac2" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_97393d7d-694d-4932-a4f9-d2752337794c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_296c57d0-f2fb-4735-9940-daf5ae308ac2" xlink:to="loc_us-gaap_DomesticPlanMember_97393d7d-694d-4932-a4f9-d2752337794c" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_008b9a43-d6a5-41db-9303-c0a10f9a6f70" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_97393d7d-694d-4932-a4f9-d2752337794c" xlink:to="loc_country_US_008b9a43-d6a5-41db-9303-c0a10f9a6f70" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_1a31720d-6759-4055-8db0-fdf7e22d9928" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_296c57d0-f2fb-4735-9940-daf5ae308ac2" xlink:to="loc_us-gaap_ForeignPlanMember_1a31720d-6759-4055-8db0-fdf7e22d9928" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/EARNINGSLOSSPERSHARESummaryDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#EARNINGSLOSSPERSHARESummaryDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/EARNINGSLOSSPERSHARESummaryDetails" xlink:type="extended" id="ie9c27624729e40c6b4761950b2812bbb_EARNINGSLOSSPERSHARESummaryDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_b2b8cd89-97a6-4a2d-a8c9-d7ee121aec17" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_048a56a1-3724-45c1-88f2-d70d1d571c1b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_b2b8cd89-97a6-4a2d-a8c9-d7ee121aec17" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_048a56a1-3724-45c1-88f2-d70d1d571c1b" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_TermOfEmploymentAgreementAndRestrictedStockAgreement_ca1c761f-124a-40de-8ec2-e3b5fdb001c9" xlink:href="iaci-20230331.xsd#iaci_TermOfEmploymentAgreementAndRestrictedStockAgreement"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_b2b8cd89-97a6-4a2d-a8c9-d7ee121aec17" xlink:to="loc_iaci_TermOfEmploymentAgreementAndRestrictedStockAgreement_ca1c761f-124a-40de-8ec2-e3b5fdb001c9" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_e3db7a52-e542-45ac-9f61-69c1998115bf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_b2b8cd89-97a6-4a2d-a8c9-d7ee121aec17" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_e3db7a52-e542-45ac-9f61-69c1998115bf" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_cb6f29fb-8699-4e80-9a3f-a79eaab9e96a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_b2b8cd89-97a6-4a2d-a8c9-d7ee121aec17" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_cb6f29fb-8699-4e80-9a3f-a79eaab9e96a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_1d8fd61d-28cf-44b6-be74-e8d96117a41e" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_cb6f29fb-8699-4e80-9a3f-a79eaab9e96a" xlink:to="loc_srt_TitleOfIndividualAxis_1d8fd61d-28cf-44b6-be74-e8d96117a41e" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1d8fd61d-28cf-44b6-be74-e8d96117a41e_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_1d8fd61d-28cf-44b6-be74-e8d96117a41e" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_1d8fd61d-28cf-44b6-be74-e8d96117a41e_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f4ca91dc-c865-477a-843c-b12014890193" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_1d8fd61d-28cf-44b6-be74-e8d96117a41e" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f4ca91dc-c865-477a-843c-b12014890193" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ChiefExecutiveOfficerMember_6284f78f-4c6e-49f2-8320-e62e8775be79" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ChiefExecutiveOfficerMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_f4ca91dc-c865-477a-843c-b12014890193" xlink:to="loc_srt_ChiefExecutiveOfficerMember_6284f78f-4c6e-49f2-8320-e62e8775be79" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_b4a9672a-135f-4918-a84b-64e1b533ed90" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_cb6f29fb-8699-4e80-9a3f-a79eaab9e96a" xlink:to="loc_us-gaap_AwardTypeAxis_b4a9672a-135f-4918-a84b-64e1b533ed90" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b4a9672a-135f-4918-a84b-64e1b533ed90_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_b4a9672a-135f-4918-a84b-64e1b533ed90" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b4a9672a-135f-4918-a84b-64e1b533ed90_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8997ed49-5a06-422f-ae3b-a2e765b13ba0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_b4a9672a-135f-4918-a84b-64e1b533ed90" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8997ed49-5a06-422f-ae3b-a2e765b13ba0" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RestrictedStockAwardsMember_0393a863-5f71-4471-b9ff-eccb62868a1e" xlink:href="iaci-20230331.xsd#iaci_RestrictedStockAwardsMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8997ed49-5a06-422f-ae3b-a2e765b13ba0" xlink:to="loc_iaci_RestrictedStockAwardsMember_0393a863-5f71-4471-b9ff-eccb62868a1e" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_0d45614f-b268-4289-adb2-958740301704" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_cb6f29fb-8699-4e80-9a3f-a79eaab9e96a" xlink:to="loc_us-gaap_PlanNameAxis_0d45614f-b268-4289-adb2-958740301704" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_0d45614f-b268-4289-adb2-958740301704_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_0d45614f-b268-4289-adb2-958740301704" xlink:to="loc_us-gaap_PlanNameDomain_0d45614f-b268-4289-adb2-958740301704_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_6ccbe3cb-b7ca-4240-9fb4-424a2f524a30" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_0d45614f-b268-4289-adb2-958740301704" xlink:to="loc_us-gaap_PlanNameDomain_6ccbe3cb-b7ca-4240-9fb4-424a2f524a30" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RSAAgreementMember_6776559f-7975-4274-9a3e-1bd35ec3b2f9" xlink:href="iaci-20230331.xsd#iaci_RSAAgreementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_6ccbe3cb-b7ca-4240-9fb4-424a2f524a30" xlink:to="loc_iaci_RSAAgreementMember_6776559f-7975-4274-9a3e-1bd35ec3b2f9" xlink:type="arc" order="0"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/FINANCIALSTATEMENTDETAILSOtherExpenseIncomeNetDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#FINANCIALSTATEMENTDETAILSOtherExpenseIncomeNetDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/FINANCIALSTATEMENTDETAILSOtherExpenseIncomeNetDetails" xlink:type="extended" id="i8860b3658cd24b48b54d4c5ba5788d2a_FINANCIALSTATEMENTDETAILSOtherExpenseIncomeNetDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOther_b2908bd9-5473-4be3-937e-e601e41edb55" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestIncomeOther"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_InterestIncomeOther_b2908bd9-5473-4be3-937e-e601e41edb55" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_a3ee5a64-79af-486d-b87e-78a02785df01" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_a3ee5a64-79af-486d-b87e-78a02785df01" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_UnrealizedGainLossOnInvestmentFollowingInitialPublicOffering_b1fcba51-df6a-48cf-834a-c627e28da783" xlink:href="iaci-20230331.xsd#iaci_UnrealizedGainLossOnInvestmentFollowingInitialPublicOffering"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_iaci_UnrealizedGainLossOnInvestmentFollowingInitialPublicOffering_b1fcba51-df6a-48cf-834a-c627e28da783" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_e7c1e313-bd6e-4287-8aa8-23b08f8a1ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_NetPeriodicDefinedBenefitsExpenseReversalOfExpenseExcludingServiceCostComponent_e7c1e313-bd6e-4287-8aa8-23b08f8a1ca9" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_f8fb95df-2e36-4e8f-a55e-bf525d0bbd27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_f8fb95df-2e36-4e8f-a55e-bf525d0bbd27" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_52388800-30b2-4a82-9085-5c44e46b4cd0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NonoperatingIncomeExpense"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_52388800-30b2-4a82-9085-5c44e46b4cd0" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_26c11dcf-97d6-415d-8c10-898c8c00b016" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_26c11dcf-97d6-415d-8c10-898c8c00b016" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_82dc5876-b8d0-4991-b5bc-e7f4bf4a42ef" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_68877aff-4ce9-490d-b8b7-fc804404e962" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_82dc5876-b8d0-4991-b5bc-e7f4bf4a42ef" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_3cbac6ce-8c59-403e-909d-09767f474896" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_82dc5876-b8d0-4991-b5bc-e7f4bf4a42ef" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_3cbac6ce-8c59-403e-909d-09767f474896" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_3cbac6ce-8c59-403e-909d-09767f474896_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_3cbac6ce-8c59-403e-909d-09767f474896" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_3cbac6ce-8c59-403e-909d-09767f474896_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_f3d3653b-cd69-46cd-a2db-1e38deb6539a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_3cbac6ce-8c59-403e-909d-09767f474896" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_f3d3653b-cd69-46cd-a2db-1e38deb6539a" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_bbf7dafd-291a-4ca9-8f8a-665d31b404e1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f3d3653b-cd69-46cd-a2db-1e38deb6539a" xlink:to="loc_us-gaap_ForeignPlanMember_bbf7dafd-291a-4ca9-8f8a-665d31b404e1" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_8b5af5d4-ad9a-477a-bd4f-4b4af1dfc05b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DomesticPlanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f3d3653b-cd69-46cd-a2db-1e38deb6539a" xlink:to="loc_us-gaap_DomesticPlanMember_8b5af5d4-ad9a-477a-bd4f-4b4af1dfc05b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_country_US_bb9fd551-0562-4326-9738-60f4c5c4cd0e" xlink:href="https://xbrl.sec.gov/country/2022/country-2022.xsd#country_US"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_8b5af5d4-ad9a-477a-bd4f-4b4af1dfc05b" xlink:to="loc_country_US_bb9fd551-0562-4326-9738-60f4c5c4cd0e" xlink:type="arc" order="1"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#RELATEDPARTYTRANSACTIONSNarrativeDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/RELATEDPARTYTRANSACTIONSNarrativeDetails" xlink:type="extended" id="iafefddd2e2e3404397909a2a0ee3c0cf_RELATEDPARTYTRANSACTIONSNarrativeDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_18977ec0-2da4-47c7-823e-afb59695d0be" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_18977ec0-2da4-47c7-823e-afb59695d0be" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_RelatedPartyVotingInterest_801a47b9-425d-42fa-a2fa-f6bfee2d304f" xlink:href="iaci-20230331.xsd#iaci_RelatedPartyVotingInterest"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_iaci_RelatedPartyVotingInterest_801a47b9-425d-42fa-a2fa-f6bfee2d304f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDueFromToRelatedParty_b161a0af-3e07-4d02-835f-f7609f7495ce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDueFromToRelatedParty"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_us-gaap_RelatedPartyTransactionDueFromToRelatedParty_b161a0af-3e07-4d02-835f-f7609f7495ce" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueFromRelatedParties_1448c5e9-d223-45c4-9382-94272f669410" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DueFromRelatedParties"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_us-gaap_DueFromRelatedParties_1448c5e9-d223-45c4-9382-94272f669410" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PercentageofOwnershipInterestHeldEachbyEntityandbyRelatedPartyinAircraftEmployingFlightCrew_de9f9743-b823-4034-9799-384026853be1" xlink:href="iaci-20230331.xsd#iaci_PercentageofOwnershipInterestHeldEachbyEntityandbyRelatedPartyinAircraftEmployingFlightCrew"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_iaci_PercentageofOwnershipInterestHeldEachbyEntityandbyRelatedPartyinAircraftEmployingFlightCrew_de9f9743-b823-4034-9799-384026853be1" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfAircraftOperated_4c1227a6-7223-4972-9ff2-823e49c4ee35" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NumberOfAircraftOperated"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_us-gaap_NumberOfAircraftOperated_4c1227a6-7223-4972-9ff2-823e49c4ee35" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PercentageOfOwnershipInterestHeldEachByEntityAndByRelatedPartyInAnotherEntityEmployingFlightCrew_85958e0b-e881-41f2-af07-c6aa2086678f" xlink:href="iaci-20230331.xsd#iaci_PercentageOfOwnershipInterestHeldEachByEntityAndByRelatedPartyInAnotherEntityEmployingFlightCrew"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_iaci_PercentageOfOwnershipInterestHeldEachByEntityAndByRelatedPartyInAnotherEntityEmployingFlightCrew_85958e0b-e881-41f2-af07-c6aa2086678f" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_PercentageOfOwnershipInterestInAircraftBySubsidiary_98c1617f-15eb-4ee6-a652-717c56de2c6e" xlink:href="iaci-20230331.xsd#iaci_PercentageOfOwnershipInterestInAircraftBySubsidiary"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_iaci_PercentageOfOwnershipInterestInAircraftBySubsidiary_98c1617f-15eb-4ee6-a652-717c56de2c6e" xlink:type="arc" order="7"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_84529f1b-2bdd-4cf2-8691-7c66b36a8119" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_10430826-90c2-4e59-9fa0-843bc7d59bff" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_84529f1b-2bdd-4cf2-8691-7c66b36a8119" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_bb9dfbb4-9281-4e98-9249-da61e5e2a49b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_84529f1b-2bdd-4cf2-8691-7c66b36a8119" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_bb9dfbb4-9281-4e98-9249-da61e5e2a49b" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_bb9dfbb4-9281-4e98-9249-da61e5e2a49b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_bb9dfbb4-9281-4e98-9249-da61e5e2a49b" xlink:to="loc_us-gaap_RelatedPartyDomain_bb9dfbb4-9281-4e98-9249-da61e5e2a49b_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_bb9dfbb4-9281-4e98-9249-da61e5e2a49b" xlink:to="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ChiefExecutiveOfficerMember_d19e3693-9301-4d76-abbb-924848ecb759" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ChiefExecutiveOfficerMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:to="loc_srt_ChiefExecutiveOfficerMember_d19e3693-9301-4d76-abbb-924848ecb759" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_BoardOfDirectorsChairmanMember_ce184e56-ef41-48ef-8235-c847012a0bc1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_BoardOfDirectorsChairmanMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:to="loc_srt_BoardOfDirectorsChairmanMember_ce184e56-ef41-48ef-8235-c847012a0bc1" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_FormerSegmentOfParentMember_c531687c-843a-4636-827a-64807e22573d" xlink:href="iaci-20230331.xsd#iaci_FormerSegmentOfParentMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:to="loc_iaci_FormerSegmentOfParentMember_c531687c-843a-4636-827a-64807e22573d" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAffiliatesMember_e4622fe7-0832-49fc-8074-5e370553dbb8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherAffiliatesMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_ef7f632d-06ac-4a06-be17-2a3f7f44e49f" xlink:to="loc_us-gaap_OtherAffiliatesMember_e4622fe7-0832-49fc-8074-5e370553dbb8" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_0ba5204d-82cb-4843-aa7d-5b2ab543ba14" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_84529f1b-2bdd-4cf2-8691-7c66b36a8119" xlink:to="loc_dei_LegalEntityAxis_0ba5204d-82cb-4843-aa7d-5b2ab543ba14" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_0ba5204d-82cb-4843-aa7d-5b2ab543ba14_default" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_0ba5204d-82cb-4843-aa7d-5b2ab543ba14" xlink:to="loc_dei_EntityDomain_0ba5204d-82cb-4843-aa7d-5b2ab543ba14_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_95da4626-d8da-44a3-ab1e-6c69fa42f696" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_0ba5204d-82cb-4843-aa7d-5b2ab543ba14" xlink:to="loc_dei_EntityDomain_95da4626-d8da-44a3-ab1e-6c69fa42f696" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_IACAndVimeoMember_6500ff85-973b-4501-a856-83bf5a8db996" xlink:href="iaci-20230331.xsd#iaci_IACAndVimeoMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_95da4626-d8da-44a3-ab1e-6c69fa42f696" xlink:to="loc_iaci_IACAndVimeoMember_6500ff85-973b-4501-a856-83bf5a8db996" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_VimeoMember_175c6f1e-f02d-4426-95ba-fdb6059c1aca" xlink:href="iaci-20230331.xsd#iaci_VimeoMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_95da4626-d8da-44a3-ab1e-6c69fa42f696" xlink:to="loc_iaci_VimeoMember_175c6f1e-f02d-4426-95ba-fdb6059c1aca" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAxis_27592397-f58c-4021-a82c-285dcf307dd1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_84529f1b-2bdd-4cf2-8691-7c66b36a8119" xlink:to="loc_us-gaap_RelatedPartyTransactionAxis_27592397-f58c-4021-a82c-285dcf307dd1" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_27592397-f58c-4021-a82c-285dcf307dd1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_27592397-f58c-4021-a82c-285dcf307dd1" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_27592397-f58c-4021-a82c-285dcf307dd1_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionDomain_b82db3a1-de55-4f16-91c4-a799bd3bed95" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RelatedPartyTransactionDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionAxis_27592397-f58c-4021-a82c-285dcf307dd1" xlink:to="loc_us-gaap_RelatedPartyTransactionDomain_b82db3a1-de55-4f16-91c4-a799bd3bed95" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_TransitionServicesAgreementMember_526b0fef-fb28-472d-91b1-3e5dda3fe998" xlink:href="iaci-20230331.xsd#iaci_TransitionServicesAgreementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_b82db3a1-de55-4f16-91c4-a799bd3bed95" xlink:to="loc_iaci_TransitionServicesAgreementMember_526b0fef-fb28-472d-91b1-3e5dda3fe998" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_LeaseAgreementMember_905b5442-4ab4-4700-9fb0-f2e685a669ab" xlink:href="iaci-20230331.xsd#iaci_LeaseAgreementMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_b82db3a1-de55-4f16-91c4-a799bd3bed95" xlink:to="loc_iaci_LeaseAgreementMember_905b5442-4ab4-4700-9fb0-f2e685a669ab" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_CorporateAircraftPurchaseMember_c46775dd-b43d-47ac-aba7-5ea12312c804" xlink:href="iaci-20230331.xsd#iaci_CorporateAircraftPurchaseMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionDomain_b82db3a1-de55-4f16-91c4-a799bd3bed95" xlink:to="loc_iaci_CorporateAircraftPurchaseMember_c46775dd-b43d-47ac-aba7-5ea12312c804" xlink:type="arc" order="2"/>
</link:definitionLink>
<link:roleRef roleURI="http://www.iac.com/role/SUBSEQUENTEVENTDetails" xlink:type="simple" xlink:href="iaci-20230331.xsd#SUBSEQUENTEVENTDetails"/>
<link:definitionLink xlink:role="http://www.iac.com/role/SUBSEQUENTEVENTDetails" xlink:type="extended" id="i087851536d5245d9b5d6090e63419760_SUBSEQUENTEVENTDetails">
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventLineItems"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireLandHeldForUse_f4c7728d-8dc2-4235-b1a3-1c2a5c2bd8fe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireLandHeldForUse"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_PaymentsToAcquireLandHeldForUse_f4c7728d-8dc2-4235-b1a3-1c2a5c2bd8fe" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireEquityMethodInvestments_f973c0f7-cb8e-42d9-b696-fbd6dcd61f13" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireEquityMethodInvestments"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_PaymentsToAcquireEquityMethodInvestments_f973c0f7-cb8e-42d9-b696-fbd6dcd61f13" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_a73343f4-cb06-44ce-b175-a24dd5bb4ced" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_a73343f4-cb06-44ce-b175-a24dd5bb4ced" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_a4cadcd5-1ced-4c62-ba5c-5137e22db0dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockSharesAcquired"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_a4cadcd5-1ced-4c62-ba5c-5137e22db0dd" xlink:type="arc" order="3"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_d414ece7-804c-4e8e-8ab4-c6f79146a822" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_d414ece7-804c-4e8e-8ab4-c6f79146a822" xlink:type="arc" order="4"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_19f93d8b-0191-4391-ab1a-0c06db234a02" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_19f93d8b-0191-4391-ab1a-0c06db234a02" xlink:type="arc" order="5"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_dc2c0e63-86be-4afd-ae64-7433f3670230" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_dc2c0e63-86be-4afd-ae64-7433f3670230" xlink:type="arc" order="6"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_bafa834d-5743-46d1-aa75-b2b315055f97" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTable"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_a1e9c059-8b47-4237-9b89-35115a11a69a" xlink:to="loc_us-gaap_SubsequentEventTable_bafa834d-5743-46d1-aa75-b2b315055f97" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_3855d7ae-a40b-42bb-8f58-203eea703688" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_bafa834d-5743-46d1-aa75-b2b315055f97" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_3855d7ae-a40b-42bb-8f58-203eea703688" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_3855d7ae-a40b-42bb-8f58-203eea703688_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_3855d7ae-a40b-42bb-8f58-203eea703688" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_3855d7ae-a40b-42bb-8f58-203eea703688_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_fbc93665-35e2-4896-92cb-c129f410c184" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_3855d7ae-a40b-42bb-8f58-203eea703688" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_fbc93665-35e2-4896-92cb-c129f410c184" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_5bb6962c-9772-46f5-a3ed-dc9cc79ffa81" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_fbc93665-35e2-4896-92cb-c129f410c184" xlink:to="loc_us-gaap_SubsequentEventMember_5bb6962c-9772-46f5-a3ed-dc9cc79ffa81" xlink:type="arc" order="0"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_931272a3-8856-4eaa-a7b0-5b7d9fd4aade" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_bafa834d-5743-46d1-aa75-b2b315055f97" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_931272a3-8856-4eaa-a7b0-5b7d9fd4aade" xlink:type="arc" order="2"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_931272a3-8856-4eaa-a7b0-5b7d9fd4aade_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_931272a3-8856-4eaa-a7b0-5b7d9fd4aade" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_931272a3-8856-4eaa-a7b0-5b7d9fd4aade_default" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_80496d67-323e-470e-bb07-45df1c073141" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_931272a3-8856-4eaa-a7b0-5b7d9fd4aade" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_80496d67-323e-470e-bb07-45df1c073141" xlink:type="arc" order="1"/>
<link:loc xlink:type="locator" xlink:label="loc_iaci_TuroMember_97c78ace-9e71-44ab-8e1d-71c3b9c3ac12" xlink:href="iaci-20230331.xsd#iaci_TuroMember"/>
<link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_80496d67-323e-470e-bb07-45df1c073141" xlink:to="loc_iaci_TuroMember_97c78ace-9e71-44ab-8e1d-71c3b9c3ac12" xlink:type="arc" order="0"/>
</link:definitionLink>
</link:linkbase>

1 Subsequent Filing that References this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/29/24  IAC Inc.                          10-K       12/31/23  157:24M

4 Previous Filings that this Filing References

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 3/01/23  IAC Inc.                          10-K       12/31/22  150:26M
 8/12/22  IAC Inc.                          8-K:5,9     8/11/22   12:306K                                   Toppan Merrill/FA
 5/26/21  IAC Inc.                          S-8 POS     5/26/21    4:138K                                   Toppan Merrill/FA
 7/02/20  IAC Inc.                          8-K:1,2,3,5 6/30/20   22:1.2M                                   Toppan Merrill/FA
↑Top
Filing Submission 0001800227-23-000016   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)
Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
About — Privacy — Redactions — Help — Fri., May 10, 11:10:20.2am ET