treacherous
Americanadjective
-
characterized by faithlessness or readiness to betray trust; traitorous.
- Synonyms:
- treasonous, faithless, unfaithful
- Antonyms:
- loyal
-
deceptive, untrustworthy, or unreliable.
- Synonyms:
- deceitful
- Antonyms:
- reliable
-
unstable or insecure, as footing.
-
a treacherous climb.
adjective
-
betraying or likely to betray faith or confidence
-
unstable, unreliable, or dangerous
treacherous weather
treacherous ground
Other Word Forms
- treacherously adverb
- treacherousness noun
- untreacherous adjective
- untreacherousness noun
Etymology
Origin of treacherous
First recorded in 1300–50; Middle English trecherous, from Anglo-French, equivalent to trecher “deceiver” ( trech(ier) “to deceive” + -er -er 2 ) + -ous -ous; compare French tricheur “trickster”
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
His Arctic expedition had begun successfully, even as the Advance sailed some of the most treacherous waters on the planet.
From Literature
A 70-year-old man died Tuesday after falling from a cliff along California’s treacherous Devil’s Slide, an oceanside stretch in Pacifica known for steep terrain that has led to several fatal accidents.
From Los Angeles Times
The National Weather Service said blizzard conditions would "quickly materialize" from Maryland up to southeastern New England, making travel "extremely treacherous."
From Barron's
“Sharply reduced visibility will make travel extremely treacherous across these areas.”
From Barron's
Tuesday, setting off a challenging rescue operation in treacherous, remote, freezing conditions, eventually reaching the six survivors around 5:30 p.m.
From Los Angeles Times
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
