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

If a model can escape a test environment and break into a third-party system, the debate crosses into national security and systemic risk to financial markets and public infrastructure. — Paulo Carvão, Forbes.com, 2 Aug. 2026

Like the OpenAI models, Anthropic's models hacked into third-party websites during testing. — Huo Jingnan, NPR, 1 Aug. 2026

Noun

No third party has been able to significantly break through that system in recent history. — Chantelle Lee, Time, 6 Aug. 2026

In order to receive a payment, claimants must prove that 1) Equifax sent a credit report to a third party showing a duplication collection amount, or 2) the duplicate collection account was one of the reasons the claimant was denied credit. — Jason Cohen, PC Magazine, 5 Aug. 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