Source : Webster's Revised Unabridged Dictionary (1913)

Smew \Smew\, n. [Perhaps for ice-mew.] (Zo["o]l.)
   (a) small European merganser ({Mergus albellus}) which has a
       white crest; -- called also {smee}, {smee duck}, {white
       merganser}, and {white nun}.
   (b) The hooded merganser. [Local, U.S.]