Webster's Revised Unabridged Dictionary · 1913

Treacher

Treacher , noun

[Old English trichour, trichur, Old French tricheor deceiver, traitor, French tricheur a cheat at play, a trickster. See Treachery.]

A traitor; a cheat. [Obsolete]
Treacher and coward both. — Beau. & Fl