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

Look for reputable brands that have been third-party tested for quality. —Heather Jones, Verywell Health, 4 June 2025

Third-Party Extensions With Excessive Permissions A major but often ignored risk is the misuse of third-party browser extensions that can access cloud content. —Expert Panel®, Forbes.com, 4 June 2025

Noun

This move could translate into a potential new revenue stream for X, which could license its content to third parties for a fee. —Jibin Joseph, PC Magazine, 6 June 2025

Musk also talked of a third party and supported the idea of impeaching Trump. —Ted Johnson, Deadline, 6 June 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