Source : Webster's Revised Unabridged Dictionary (1913)

Oarfish \Oar"fish`\ ([=o]r"f[i^]sh`), n. (Zo["o]l.)
   The ribbon fish.

Source : WordNet®

oarfish
     n : thin deep-water tropical fish 20 to 30 feet long having a
         red dorsal fin [syn: {king of the herring}, {ribbonfish},
          {Regalecus glesne}]
     [also: {oarfishes} (pl)]