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

If they are used on the road, the driver needs to fulfil a certain criteria, including having a driving license, at least third party insurance and obligatory lamps, reflectors and rear markings fitted.

From BBC • Apr. 2, 2026

While companies say they protect your data, any information that’s collected has the potential to be stolen or misused by an employee or third party, Schwartz says.

From The Wall Street Journal • Mar. 20, 2026

Lawyers already are barred under the State Bar’s rules from allowing a third party to dictate case strategy and are barred in many cases from sharing legal fees with a nonlawyer.

From Los Angeles Times • Mar. 17, 2026

Any prospective heirs will then have to rely on their own skills to build their finances, rather than relying on a third party.

From MarketWatch • Mar. 16, 2026

"Yes, sir, he put through the sale—though he made it clear that he was buying Soldier Island for a third party, unnamed."

From "And Then There Were None" by Agatha Christie

Related Words

• mediator