Source : Webster's Revised Unabridged Dictionary (1913)

Cowfish \Cow"fish`\ (-f?ch`), n. (Zo["o]l.)
   (a) The grampus.
   (b) A California dolphin ({Tursiops Gillii}).
   (c) A marine plectognath fish ({Ostracoin quadricorne}, and
       allied species), having two projections, like horns, in
       front; -- called also {cuckold}, {coffer fish},
       {trunkfish}.

Source : WordNet®

cowfish
     n : trunkfish having hornlike spines over the eyes [syn: {Lactophrys
         quadricornis}]
     [also: {cowfishes} (pl)]