Source : Webster's Revised Unabridged Dictionary (1913)

Doucker \Douck"er\, n. [From aouck, for duck. See {Duck}, v. t.]
   (Zo["o]l.)
   A grebe or diver; -- applied also to the golden-eye, pochard,
   scoter, and other ducks. [Written also {ducker}.] [Prov.
   Eng.]