treacherous
TREH-chuh-ruhs
/ˈtretʃərəs/
Guilty of or involving betrayal or deception; also used to describe hazardous physical conditions.
Can describe a person who is untrustworthy or a physical environment (like an icy road) that looks safe but is actually dangerous.
The story behind the word. Treacherous comes from the Old French 'trecheur' (deceiver), which derives from 'trechier' (to trick or cheat). This is linked to the Vulgar Latin 'tricare', meaning to play tricks or perplex. The word has always carried the sense of a trap waiting to be sprung.
Word relationships
- perilous: Perilous simply means very dangerous, while treacherous implies a hidden or deceptive hazard.
- reliable: Reliable means consistently good in quality or performance, completely free of hidden dangers.
Commonly confused with
- mischievous: Mischievous means playfully annoying, while treacherous means dangerously deceptive.
Word family
- treachery (noun): Violation of allegiance or of faith and confidence.
Collocations
- treacherous road
- treacherous waters
- treacherous ally
Idioms & expressions
- skating on thin ice
Example sentences
- "The mountain pass was treacherous, covered in a thin layer of black ice that was nearly invisible to drivers." A description of hazardous winter travel conditions.
Memory hook
Think of a 'treacherous teacher' who promises an easy test but secretly makes it incredibly difficult. A hidden trap under ice.
When not to use
Do not use to describe a simple, obvious danger; it must involve some element of hidden danger or deception.
Fun facts
- In Dante's Inferno, the ninth and deepest circle of Hell is reserved specifically for those who committed acts of treachery.
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