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

Related Words

• mediator