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

The notorious bidding war for a Palm Beach estate between Trump and Jeffrey Epstein involved a third party.

From Salon • Jun. 9, 2026

Some of these were booked by third party resellers using bots with the intention of charging inflated prices but were unable to sell them, the BBC understands.

From BBC • Jun. 8, 2026

Insurers report as “affiliated” debt or equity of an affiliate as well as investments sold by an affiliate but backed by a third party.

From The Wall Street Journal • May 26, 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

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

From "Endgame" by Frank Brady

Related Words

• mediator