The Collaborative International Dictionary of English v.0.48:

Widgeon \Widg"eon\, n. [Probably from an old French form of F.
   vigeon, vingeon, gingeon; of uncertain origin; cf. L. vipio,
   -onis, a kind of small crane.] (Zool.)
   Any one of several species of fresh-water ducks, especially
   those belonging to the subgenus Mareca, of the genus
   Anas. The common European widgeon (Anas penelope) and the
   American widgeon (Anas Americana) are the most important
   species. The latter is called also baldhead, baldpate,
   baldface, baldcrown, smoking duck, wheat, duck, and
   whitebelly.
   [1913 Webster]

   Bald-faced widgeon, or Green-headed widgeon, the American
      widgeon.

   Black widgeon, the European tufted duck.

   Gray widgeon.
   (a) The gadwall.
   (b) The pintail duck.

   Great headed widgeon, the poachard.

   Pied widgeon.
   (a) The poachard.
   (b) The goosander.

   Saw-billed widgeon, the merganser.

   Sea widgeon. See in the Vocabulary.

   Spear widgeon, the goosander. [Prov. Eng.]

   Spoonbilled widgeon, the shoveler.

   White widgeon, the smew.

   Wood widgeon, the wood duck.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Anas penelope
    n 1: freshwater duck of Eurasia and northern Africa related to
         mallards and teals [syn: widgeon, wigeon, Anas
         penelope]