The Collaborative International Dictionary of English v.0.48:

Bluewing \Blue"wing`\, n. (Zool.)
   The blue-winged teal. See Teal.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bluewing
    n 1: American teal [syn: bluewing, blue-winged teal, Anas
         discors]