Source : Webster's Revised Unabridged Dictionary (1913)

Buffel duck \Buf"fel duck\ (b[u^]f"f[e^]l d[u^]k`). [See
   {Buffalo}.] (Zo["o]l.)
   A small duck ({Charitonetta albeola}); the spirit duck, or
   butterball. The head of the male is covered with numerous
   elongated feathers, and thus appears large. Called also
   {bufflehead}.