Treachery
Treachery , noun
[Old English trecherie, trichere, Old French trecherie, tricherie, French tricherie trickery, from tricher to cheat, to trick, Old French trichier, trechier; probably of Teutonic origin. See Trickery, Trick.]
Violation of allegiance or of faith and confidence; treasonable or perfidious conduct; perfidy; treason.
Be ware, ye lords, of their treachery.
In the council chamber at Edinburgh, he had contracted a deep taint of treachery and corruption.