Source : Webster's Revised Unabridged Dictionary (1913)

Sheepshead \Sheeps"head`\, n. [So called because of the fancied
   resemblance of its head and front teeth to those of a sheep.]
   (Zo["o]l.)
   A large and valuable sparoid food fish ({Archosargus, or
   Diplodus, probatocephalus}) found on the Atlantic coast of
   the United States. It often weighs from ten to twelve pounds.

   Note: The name is also locally, in a loose way, applied to
         various other fishes, as the butterfish, the
         fresh-water drumfish, the parrot fish, the porgy, and
         the moonfish.

Source : WordNet®

sheepshead
     n : large (up to 20 lbs) food fish of the eastern coast of the
         United States and Mexico [syn: {Archosargus
         probatocephalus}]