third-party

1 of 2

adjective

third-par·​ty ˈthərd-ˈpär-tē 

1

: of, relating to, or involving a third party

third-party insurance

2

: of, relating to, or being software that is created by a vendor to be compatible with the products of another vendor

third party

2 of 2

noun

1

: a person other than the principals

a third party to a divorce proceeding

insurance against injury to third parties

2

a

: a major political party operating over a limited period of time in addition to two other major parties in a nation or state normally characterized by a two-party system

b

: minor party

Examples of third-party in a Sentence

Recent Examples on the Web

Adjective

The companies also seem to be building in-house teams to develop custom generative-AI models, while also using third-party software. — Los Angeles Times, 26 July 2026

Tulsa's program has a third-party evaluation with a comparison group, and the largest commitments in the country deserve the same, not least because a model performing this well has every reason to welcome the audit that proves it. — Tonya M. Evans, Forbes.com, 26 July 2026

Noun

But this replacement adoption has strings attached, in the form of a father (Fabrizio Odetto) who’d already been trying to get Giulia away from his dissolute ex, and is not about to hand her over to some rich third party. — Dennis Harvey, Variety, 30 July 2026

The plaintiffs said studios will now be dissuaded from buying the rights to the movie, knowing that a version of it could be released by a third party for free. — Mary Cunningham, CBS News, 30 July 2026

Word History

First Known Use

Adjective

1901, in the meaning defined at sense 1

Noun

1641, in the meaning defined at sense 1

Kids Definition

third party

noun

1

: a person other than the main participants

a third party to the legal proceedings

2

a

: a political party operating usually for a limited time in addition to the two major parties in a 2-party system

b

: minor party

Legal Definition

third party

see also:

party sense 1a, b