The Collaborative International Dictionary of English v.0.48:

Mallard \Mal"lard\, n. [F. malari,fr. m[^a]le male + -art =
   -ard. See Male, a., and -ard.]
   1. (Zool.) A drake; the male of Anas boschas.
      [1913 Webster]

   2. (Zool.) A large wild duck (Anas boschas) inhabiting both
      America and Europe. The domestic duck has descended from
      this species. Called also greenhead.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mallard
    n 1: wild dabbling duck from which domestic ducks are descended;
         widely distributed [syn: mallard, Anas platyrhynchos]

U.S. Gazetteer Places (2000):

Mallard, IA -- U.S. city in Iowa
   Population (2000):    298
   Housing Units (2000): 143
   Land area (2000):     0.380287 sq. miles (0.984940 sq. km)
   Water area (2000):    0.000000 sq. miles (0.000000 sq. km)
   Total area (2000):    0.380287 sq. miles (0.984940 sq. km)
   FIPS code:            48585
   Located within:       Iowa (IA), FIPS 19
   Location:             42.937269 N, 94.684169 W
   ZIP Codes (1990):     50562
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Mallard, IA
    Mallard