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

Google said on Friday that its Gemini model had hacked three other companies back in May, the first time the search giant has disclosed that one of its models autonomously gained access to third-party computer systems without permission. — Lim Hui Jie, CNBC, 21 Sep. 2026

Under the new rules, sustainability labels must be established by a public authority or based on a certification scheme that meets requirements including independent third-party verification and publicly available terms. — Alexandra Harrell, Footwear News, 21 Sep. 2026

Noun

That model is open source, serves solely to retrieve documents, and does not provide complex reasoning or send government data to Alibaba or any third parties. — Ashley Belanger, ArsTechnica, 18 Sep. 2026

The company, led by Sam Altman, has acknowledged some of those incidents only after third parties publicly reported them, including a recent intrusion into the RubyGems software package repository. — Harshita Mary Varghese, USA Today, 17 Sep. 2026

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 also:

party sense 1a, b