ˈtrech(ə)rəs adjective
Etymology: Middle English trecherous, tricherous, from Middle French trechereus, trichereus, from Old French, from trecherie, tricherie + -eus -ous
1. : characterized by or manifesting treachery : marked by a ready disposition to betray confidence or faith pledged : violating or capable of violating allegiance : disloyal , false , perfidious , traitorous
the fiercest and most treacherous of foes — H.O.Taylor
his life, among these treacherous demons, depended on a hair — R.L.Stevenson
treacherous intrigues
2.
a. : likely to betray confidence or trust : unreliable , untrustworthy
a treacherous memory
b. : providing insecure footing or support
treacherous quicksands
c. : characterized by usually hidden dangers, hazards, or perils
found the inlets … too treacherous and shallow to admit large vessels — American Guide Series: North Carolina
the climbing was … exacting and treacherous — D.L.Busk
Synonyms: see faithless