Source : Webster's Revised Unabridged Dictionary (1913)

Plyer \Ply"er\, n.
   One who, or that which, plies; specifically:
   (a) pl. A kind of balance used in raising and letting down a
       drawbridge. It consists of timbers joined in the form of
       a St. Andrew's cross.
   (b) pl. See {Pliers}.

Source : WordNet®

plyer
     n : someone who plies a trade [syn: {plier}]