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

Whether it's covered by a traditional insurance policy or an AOL, the need for a third party to validate and stand behind ownership remains. —Marc Shaw, Forbes.com, 18 Aug. 2025

The lawsuit concerned what Hall said was Oates' plan to sell a portion of their joint venture Whole Oats Enterprises to a third party. —Evan Mealins, The Tennessean, 15 Aug. 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