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

• 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

Thus far, this prosecution, and a corresponding case against the gang in Sacramento, have been rife with evidence of treachery and violence inside and outside of prison. —Nate Gartrell, Mercury News, 31 July 2025

The six-parter, to debut July 14, follows six groups of friends, and six historical cases of murder and treachery among them. —Etan Vlessing, HollywoodReporter, 19 June 2025

But amid the bloodbaths and treacheries, Westeros still penciled in time for a little romance — some more compelling than others (Jon and Ygritte > Jon and Daenerys). —Tyler Aquilina, EW.com, 17 Apr. 2025

In true Christie fashion, the Tressilian reunion inevitably leads to murder, familial treachery, and a labyrinthine hunt for the killer. —Erik Morse, Vogue, 15 Apr. 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