- The definition of treacherous is someone who is guilty of dishonesty or betrayal, or something that is dangerous or hazardous.
- 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.
- 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)