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

In Rockefeller’s defense, as a business owner, you would rather have a job done by your own trusted people than pay an unknown third party to handle the task.

From Barron's • May 2, 2026

First, contact the Department of Education and your loan servicer and revoke any authorization you granted to a third party related to your loan.

From MarketWatch • Apr. 30, 2026

In a blind trust, relevant parties transfer their shares to independent trustees, whereby all the decision-making of the club will rest solely under the control of the third party.

From BBC • Apr. 27, 2026

Neither Party shall disclose, reproduce, disseminate, use, or permit any third party to disclose, reproduce, disseminate, or use any Confidential Information without the prior written consent of the Confiding Party.

From The Wall Street Journal • Apr. 23, 2026

Any third party whom you might make their commander cannot immediately seize enough authority to harm you.

From "The Prince" by Niccolò Machiavelli

Related Words

• mediator