treacherous

[ trech-er-uhs ]
See synonyms for: treacheroustreacherouslytreacherousness on Thesaurus.com

adjective
  1. characterized by faithlessness or readiness to betray trust; traitorous.

  2. deceptive, untrustworthy, or unreliable.

  1. unstable or insecure, as footing.

  2. dangerous; hazardous: a treacherous climb.

Origin of treacherous

1
First recorded in 1300–50; Middle English trecherous, from Anglo-French, equivalent to trecher “deceiver” (trech(ier) “to deceive” + -er -er2) + -ous -ous; compare French tricheur “trickster”

Other words for treacherous

Opposites for treacherous

Other words from treacherous

  • treach·er·ous·ly, adverb
  • treach·er·ous·ness, noun
  • un·treach·er·ous, adjective
  • un·treach·er·ous·ness, noun

Words Nearby treacherous

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How to use treacherous in a sentence

British Dictionary definitions for treacherous

treacherous

/ (ˈtrɛtʃərəs) /


adjective
  1. betraying or likely to betray faith or confidence

  2. unstable, unreliable, or dangerous: treacherous weather; treacherous ground

Derived forms of treacherous

  • 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