Source : Webster's Revised Unabridged Dictionary (1913)

Mallard \Mal"lard\, n. [F. malari,fr. m[^a]le male + -art =-ard.
   See {Male}, a., and {-ard}.]
   1. (Zo["o]l.) A drake; the male of {Anas boschas}.

   2. (Zo["o]l.) A large wild duck ({Anas boschas}) inhabiting
      both America and Europe. The domestic duck has descended
      from this species. Called also {greenhead}.

Source : WordNet®

mallard
     n : wild dabbling duck from which domestic ducks are descended;
         widely distributed [syn: {Anas platyrhynchos}]