- An example of treacherous is someone you thought was your friend who shares your secrets with everyone.
- An example of treacherous is ground made slippery because of an ice storm.
The definition of treacherous is someone who is guilty of dishonesty or betrayal, or something that is dangerous or hazardous.
- characterized by treachery; traitorous; disloyal; perfidious
- giving a false appearance of safety or reliability; untrustworthy or insecure: treacherous rocks
Origin of treacherousMiddle English trecherous from Old French trecheros
- Guilty of or characterized by betrayal of confidence or trust; perfidious.
- Characterized by unforeseen or hidden hazards; dangerous or deceptive: treacherous waters; treacherous footing.
(comparative more treacherous, superlative most treacherous)