The Collaborative International Dictionary of English v.0.48:

Anseres \An"se*res\, n. pl. [L., geese.] (Zool.)
   A Linn[ae]an order of aquatic birds swimming by means of
   webbed feet, as the duck, or of lobed feet, as the grebe. In
   this order were included the geese, ducks, auks, divers,
   gulls, petrels, etc.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Anseres
    n 1: used in some especially older classifications; coextensive
         with the family Anatidae [syn: Anseres, suborder
         Anseres]