Definition of treachery

< treacherous

treacle >

treach·er·y    (trch-r) KEY 

NOUN:
pl. treach·er·ies

1. Willful betrayal of fidelity, confidence, or trust; perfidy.
2. The act or an instance of such betrayal.

---

ETYMOLOGY:
Middle English trecherie, from Old French, from trichier, to trick, probably from Vulgar Latin *triccre ; see trick