follow Dictionary.com

Stories We Like: A Guide to the Comma

treacherous

[trech-er-uh s] /ˈtrɛtʃ ər əs/
adjective
1.
characterized by faithlessness or readiness to betray trust; traitorous.
2.
deceptive, untrustworthy, or unreliable.
3.
unstable or insecure, as footing.
4.
dangerous; hazardous:
a treacherous climb.
Origin
1300-1350
1300-50; Middle English trecherous < Anglo-French, equivalent to trecher deceiver (trech(ier) to deceive + -er -er2) + -ous -ous. Cf. French tricheur trickster
Related forms
treacherously, adverb
treacherousness, noun
untreacherous, adjective
untreacherously, adverb
untreacherousness, noun
Synonyms
1. unfaithful, faithless, treasonous. 2. deceitful.
Antonyms
1. loyal. 2. reliable.
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
British Dictionary definitions for treacherousness

treacherous

/ˈtrɛtʃərəs/
adjective
1.
betraying or likely to betray faith or confidence
2.
unstable, unreliable, or dangerous treacherous weather, treacherous ground
Derived Forms
treacherously, adverb
treacherousness, 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
Cite This Source
Word Origin and History for treacherousness

treacherous

adj.

early 14c., from Old French trecheros (12c.), from trecheur, agent noun from trechier "to cheat, trick" (see trick). Figuratively, of things, from c.1600. Related: Treacherously; treacherousness.

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source

Word of the Day

Difficulty index for treacherous

Many English speakers likely know this word

Word Value for treacherousness

20
0
Scrabble Words With Friends

Quotes with treacherousness

Nearby words for treacherousness