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Synonyms

third party

American  

noun

  1. any party to an incident, case, quarrel, etc., who is incidentally involved.

  2. (in a two-party system) a political party formed as a dissenting or independent group from members of one or both of the two prevailing major parties.

third party British  

noun

  1. a person who is involved by chance or only incidentally in a legal proceeding, agreement, or other transaction, esp one against whom a defendant claims indemnity

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

adjective

  1. insurance providing protection against liability caused by accidental injury or death of other persons or damage to their property

    third-party insurance
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of third party

An Americanism dating back to 1795–1805

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

It’s hard to find an eyewitness or reliable third party who can vouch for what took place between people behind closed doors.

From Los Angeles Times • Apr. 17, 2026

The firm has said its methodologies are audited annually by an independent third party.

From The Wall Street Journal • Apr. 17, 2026

Are you tenants in common, where one party can leave their share to a third party?

From MarketWatch • Apr. 16, 2026

Goldman says this strategy is simply a workaround to hold platforms accountable for problematic third party content it publishes.

From Salon • Apr. 16, 2026

The third party he presumed responsible was the United States government.

From "Endgame" by Frank Brady

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.