Source : Webster's Revised Unabridged Dictionary (1913)

Treacher \Treach"er\, n. [OE. trichour, trichur, OF. tricheor
   deceiver, traitor, F. tricheur a cheat at play, a trickster.
   See {Treachery}.]
   A traitor; a cheat. [Obs.]

         Treacher and coward both.                --Beau. & Fl.