third party

American  

noun

third parties plural

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

Other Word Forms

Noun Inflected Forms

• third parties
  plural

Etymology

Origin of third party

An Americanism dating back to 1795–1805

Example Sentences

See Examples For:

third party

Domani plays a prominent role in New York City’s construction industry, acting as an independent third party to inspect work sites to ensure construction complies with safety codes.

From The Wall Street Journal ● Jul. 27, 2026

The DPS letter said inaccurate information recorded about Lorraine on police systems had been shared with others and defamatory information about her was passed by a third party to her GP.

From BBC ● Jul. 2, 2026

But first, a gentle warning: Your brother could sell his share to a third party.

From MarketWatch ● Jun. 24, 2026

As third party delivery services such as DoorDash grew in popularity, Pizza Hut fell behind without the advantage of delivery convenience, said Aneurin Canham-Clyne, a reporter for trade publication Restaurant Drive.

From Los Angeles Times ● Jun. 16, 2026

Somebody, a third party, agreed the fishing had gone sour, the bank seemed all dried up real sudden, he’d been thinking on fishing at Elliot Head, couldn’t tell but maybe things was better there.

From "Snow Falling on Cedars: A Novel" by David Guterson

Related Words

• mediator