treachery

noun

treach·​ery ˈtre-chə-rē 

ˈtrech-rē

plural treacheries

1

: violation of allegiance or of faith and confidence : treason

2

: an act of perfidy or treason

Synonyms of treachery

• betrayal
• treason

Examples of treachery in a Sentence

a tale of treachery and revenge

was furious that she revealed his secret and never forgave her for the treachery

Recent Examples on the Web

As Isaac told it, his kingdom’s history is rife with treachery, usurpation, and murder. —Jon Lee Anderson, New Yorker, 24 Nov. 2025

Tarabay leads the cast as the titular Ashur, now thriving after his treachery. —Randall Colburn, Entertainment Weekly, 3 Nov. 2025

But peek behind the veil, and a different reality reveals itself: a dog-eat-dog world of power struggles, artifice, hubris, treachery, and duplicity—yet also an enormous amount of sacrifice. —Foreign Affairs, 20 Oct. 2025

And when the surviving crew interrogates the android Ash about his treachery, the book has him pretty much spill the space beans. —Daniel Dockery, Vulture, 22 Sep. 2025

Word History

Etymology

Middle English trecherie, from Anglo-French, from trecher, tricher to deceive, from Vulgar Latin *triccare — more at trick entry 1

First Known Use

13th century, in the meaning defined at sense 1

Rhymes for treachery

• lechery

Kids Definition

treachery

noun

treach·​ery ˈtrech-(ə-)rē 

plural treacheries

1

: violation of allegiance or of faith and confidence : treason

2

: an act of treason