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 benefits of third-party testing are wide-ranging. —Brynn Cooksey, Forbes.com, 7 Sep. 2025

In an August memo to the Board of Supervisors, Martinez proposed hiring a third-party administrator to oversee jail health care instead. —Kelly Davis, San Diego Union-Tribune, 7 Sep. 2025

Noun

That means your contract will be administered by a third party, American Auto Shield, which can complicate the claims approval process. —Brian Sloan, CNBC, 4 Sep. 2025

The rules, according to an NFL spokesman, covered NIL and sponsorship deals, but also equity investments in collectives or other third parties facilitating payments to college stars. —Eben Novy-Williams, Sportico.com, 4 Sep. 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