adjective

traitorous

TRAY-ter-us/ˈtreɪtərəs/

Disloyal in a way that betrays trust.

The rebels view his secret deal as a traitorous act.

During a team flag game, a blue-team member secretly hands her own team's flag to a red-team opponent behind the back of her unsuspecting teammate.

Etymology

French traitros, based on the word for a traitor, is the apparent source of traitorous. The English adjective broadened from disloyalty to a country or sovereign to faithlessness more generally.

In context

PragerU2:15

Some Americans believed their refusal to salute the flag was disloyal and even traitorous.

West Virginia v. Barnette: Forcing the Pledge of Allegiance? | 5-Minute Videos | PragerU

More examples

Sharing our confidential plans with a rival is traitorous.
She refuses to take part in their traitorous plot.
His traitorous behavior destroys the team's trust in him.

Forms

traitorous

traitor noun — Someone who betrays a person, country, or cause.

traitorously adverb — In a way that betrays someone's trust.

Similar words

disloyal: Broader term for lacking loyalty, without necessarily actively betraying trust.
treacherous: Emphasizes deception or hidden danger in a betrayal.
treasonous: Specifically concerns betrayal of one's country, often through criminal acts.