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

Trump’s order prohibits third-party collectives from offering direct pay-for-play deals, insists NIL must be tied to real brand value, and mandates that colleges above certain revenue thresholds maintain or expand funding and participation in women’s and Olympic sports. —Aaron S. Marks, Hartford Courant, 15 Aug. 2025

While the certification was not specifically a result of litigation, pursuing rigorous, third-party validation of AI practices is increasingly viewed as an industry best practice. —Marc Blythe, Forbes.com, 15 Aug. 2025

Noun

Here's how to get back on the right path Editorial Note: Opinions, analyses, reviews or recommendations expressed in this article are those of the Select editorial staff’s alone, and have not been reviewed, approved or otherwise endorsed by any third party. —Jasmin Suknanan, CNBC, 4 Aug. 2025

After an initial report was made by a third party on Sunday, officers and ambulance workers were deployed to the camp in the village of Stathern, Leicestershire, central England, where the children were assessed. —Lianne Kolirin, CNN Money, 31 July 2025

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 party sense 1a, b