The Collaborative International Dictionary of English v.0.48:

Water ousel \Wa"ter ou"sel\, Water ouzel \Wa"ter ou"zel\ .
   (Zool.)
   Any one of several species of small insessorial birds of the
   genus Cinclus (or Hydrobates), especially the European
   water ousel (Cinclus aquaticus), and the American water
   ousel (Cinclus Mexicanus). These birds live about the
   water, and are in the habit of walking on the bottom of
   streams beneath the water in search of food.
   [1913 Webster]

WordNet (r) 3.0 (2006):

water ouzel
    n 1: small stocky diving bird without webbed feet; frequents
         fast-flowing streams and feeds along the bottom [syn:
         water ouzel, dipper]