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1. Guilty of or characterized by betrayal of confidence or trust; perfidious.
2. Characterized by unforeseen or hidden hazards; dangerous or deceptive: treacherous waters; treacherous footing.

treach′er·ous·ly adv.
treach′er·ous·ness n.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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1. Willful betrayal of fidelity, confidence, or trust:
The American Heritage® Roget's Thesaurus. Copyright © 2013, 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
خِيانَه، غَدْر


(= disloyalty) the treacherousness of these generalsdiese verräterischen Generäle
(= unreliability: of memory etc) → Unzuverlässigkeit f
(of road/weather conditions)Tücke f, → Gefährlichkeit f; because of the treacherousness of the snowwegen der trügerischen Schneeverhältnisse
Collins German Dictionary – Complete and Unabridged 7th Edition 2005. © William Collins Sons & Co. Ltd. 1980 © HarperCollins Publishers 1991, 1997, 1999, 2004, 2005, 2007


(ˈtretʃərəs) adjective
1. betraying or likely to betray. a treacherous person/act.
2. dangerous. The roads are treacherous in winter.
ˈtreacherously adverb
ˈtreacherousness noun
ˈtreachery noun
(an act of) betraying someone; disloyalty. His treachery led to the capture and imprisonment of his friend.
Kernerman English Multilingual Dictionary © 2006-2013 K Dictionaries Ltd.
References in periodicals archive ?
There's an openness to Arlan's travelogue that makes it easy to underestimate the scope of his journey, and the treacherousness -- though he does mention rainstorms and chilling mistakes.
To dikract ourselves for a bit from the treacherousness of the road, Steven and I reminisced quietly about other trips, to this island, to others, to places 'farther flung.
However, due to their treacherousness, bogs have become associated with desolate and dangerous places, and therefore are seen as strengthening the image of the isolationism of their nearby areas.
(6) Like his Muscovite ancestors, who felt seduced by Latin "treacherousness" and German "cunning," Bolotov was concerned about the attraction that Europe exercised over himself and his compatriots.
Like the Irish criminal, Barton gradually senses the treacherousness of writing-confession and realizes that the corollary of the impossibility of rendering authentic her narrative has been the inescapable association of her story with Friday, the tongueless ex-servant of Cruso.
Allison Berg also notes the treacherousness of this particular theme in Quicksand: "Given the persistent stereotypes of black women's sexuality, Helga--a single and sensual black woman who scorns marriage and middle-class respectability--makes a particularly dangerous subject" (104).
Not only was the state part of the country's last frontier, it was reputed to have perfect weather, an astoundingly beautiful topography (whose treacherousness had yet to be fully appreciated), and an elastic social structure.