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.

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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

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adjective

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

   third-party insurance

Etymology

Origin of third party

An Americanism dating back to 1795–1805

Example Sentences

There is a green party, the ADPD, but no third party has held even a seat in Malta's parliament since before independence in 1964.

From Barron's • May 31, 2026

But prices of those tokens cratered after people on social media pointed to guidance that OpenAI and Anthropic issued saying they wouldn’t honor stakes that had been transferred to a third party using an SPV.

From MarketWatch • May 20, 2026

New government rules now mean only a learner driver can book their own test, part of a crackdown on third party operators using bots to hoover up thousands of slots.

From BBC • May 16, 2026

Genesis Minerals “remains the obvious third party with clear strategic benefits in the Leonora region,” Hissey says.

From The Wall Street Journal • May 5, 2026

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

From "Endgame" by Frank Brady

Related Words

• mediator