Dictionary.com

treacherous

[ trech-er-uhs ]
/ ˈtrɛtʃ ər əs /
Save This Word!
See synonyms for: treacherous / treacherously / treacherousness on Thesaurus.com

adjective
characterized by faithlessness or readiness to betray trust; traitorous.
deceptive, untrustworthy, or unreliable.
unstable or insecure, as footing.
dangerous; hazardous: a treacherous climb.
QUIZ
QUIZ YOURSELF ON AFFECT VS. EFFECT!
In effect, this quiz will prove whether or not you have the skills to know the difference between “affect” and “effect.”
Question 1 of 7
The rainy weather could not ________ my elated spirits on my graduation day.
Meet Grammar CoachWrite or paste your essay, email, or story into Grammar Coach and get grammar helpImprove Your Writing
Meet Grammar CoachImprove Your Writing
Write or paste your essay, email, or story into Grammar Coach and get grammar help

Origin of treacherous

1300–50; Middle English trecherous<Anglo-French, equivalent to trecher deceiver (trech(ier) to deceive + -er-er2) + -ous-ous. Cf. French tricheur trickster

OTHER WORDS FROM treacherous

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use treacherous in a sentence

British Dictionary definitions for treacherous

treacherous
/ (ˈtrɛtʃərəs) /

adjective
betraying or likely to betray faith or confidence
unstable, unreliable, or dangeroustreacherous weather; treacherous ground

Derived forms of treacherous

treacherously, adverbtreacherousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
FEEDBACK