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

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

"A planned attack preceded by reconnaissance, and which was ordered by a third party acting on behalf of the Iranian state," he said.

From BBC • May 18, 2026

The company believes this LLM will give it a competitive advantage and control over AI costs, “with little to no reliance on third party LLMs,” Abrahami added.

From Barron's • May 13, 2026

A man that thinks anything he dont understand all about must be crooked and that first chance he gets he’s morally bound to tell the third party what’s none of his business to tell.

From "The Sound and the Fury" by William Faulkner

Related Words

• mediator