Source : Webster's Revised Unabridged Dictionary (1913)

Pinfish \Pin"fish`\, n. [So called from their sharp dorsal
   spines.] (Zo["o]l.)
   (a) The sailor's choice ({Diplodus, or Lagodon, rhomboides}).
   (b) The salt-water bream ({Diplodus Holbrooki}).

   Note: Both are excellent food fishes, common on the coast of
         the United States south of Cape Hatteras. The name is
         also applied to other allied species.