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

Fifteen years ago, former Republican Congressman Tom Tancredo ran as a third-party candidate and got 36% of the vote. —Shaun Boyd, CBS News, 6 Jan. 2026

In May, Stord bought third-party delivery company and UPS subsidiary Ware2Go for an undisclosed amount earlier this year. —Samantha Subin, CNBC, 5 Jan. 2026

Noun

Firefighters who returned the next day complained to Battalion Chief Mario Garcia that the ground was still smoldering and rocks still felt hot to the touch, according to private text messages from three firefighters to a third party that were reviewed by The Times. —Paul Pringle, Los Angeles Times, 31 Dec. 2025

Certain information has been provided by and/or is based on third party sources and, although such information is believed to be reliable, no representation is made with respect to the accuracy, completeness, or timeliness of such information. —Katie Stockton, CNBC, 29 Dec. 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