Treach·er·y n. Violation of allegiance or of faith and confidence; treasonable or perfidious conduct; perfidy; treason.
Be ware, ye lords, of their treachery. --Chaucer.
In the council chamber at Edinburgh, he had contracted a deep taint of treachery and corruption. --Macaulay.
n 1: betrayal of a trust [syn: perfidy, perfidiousness]
2: an act of deliberate betrayal [syn: betrayal, treason, perfidy]