Definition of treacherous in English:

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Pronunciation: /ˈtreCH(ə)rəs/


1Guilty of or involving betrayal or deception: a treacherous Gestapo agent memory is particularly treacherous
More example sentences
  • Josh had been promoted recently because of a treacherous betrayal by the old Number Four.
  • For example, he embodied animals that were weak, cowardly, false, and treacherous.
  • They are not deceitful or treacherous in their conduct and are faithful to their oaths and promises.
traitorous, disloyal, faithless, unfaithful, duplicitous, deceitful, deceptive, false, backstabbing, double-crossing, double-dealing, two-faced, Janus-faced, weaselly, untrustworthy, unreliable;
apostate, renegade, two-timing
literary perfidious
1.1(Of ground, water, conditions, etc.) hazardous because of presenting hidden or unpredictable dangers: a vacationer was swept away by treacherous currents
More example sentences
  • My inertia in not pushing it backwards into a safe zone is as guilty for the shattered glass as the treacherous wind.
  • On that day Couples' tee-shot to Golden Bell, the treacherous par three, clung miraculously to the bank of the Creek.
  • The views open out to the north-east, across the treacherous Pentland Firth to Orkney, as you reach Portskerra pier.
dangerous, hazardous, perilous, unsafe, precarious, risky, deceptive, unreliable
informal dicey, hairy



Pronunciation: /ˈtreCH(ə)rəslē/
Example sentences
  • As it was, hopeful rather than thoughtful balls were plummeted into a two man full-forward line that had virtually no chance of securing possession given the tendency of the ball to skid away from them on the treacherously greasy surface.
  • It rained heavily during the afternoon, which made the stages very muddy and treacherously slippy.
  • I defy anyone who hasn't read the book to decipher this film, to understand the implications, motivations and emotional complexities of a story dependent on treacherously subtle codes of conduct.


Pronunciation: /ˈtreCH(ə)rəsnəs/
Example sentences
  • The introduction speaks of the harshness and treacherousness of the Antarctic - so much so that I actually felt a chill.
  • Fairbanks is made out to be a pretty dangerous town with flights in the winter operating perhaps only a few times a week due to the difficulty and treacherousness of getting around the ice fog.
  • Thus far, their collected data confirm the treacherousness of the bottom.


Middle English (in the sense 'involving betrayal'): from Old French trecherous, from trecheor 'a cheat', from trechier 'to cheat'.

Words that rhyme with treacherous


For editors and proofreaders

Syllabification: treach·er·ous

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