Source : Webster's Revised Unabridged Dictionary (1913)

Herring \Her"ring\, n. [OE. hering, AS. h[ae]ring; akin to D.
   haring, G. h["a]ring, hering, OHG. haring, hering, and prob.
   to AS. here army, and so called because they commonly move in
   large numbers. Cf. {Harry}.] (Zo["o]l.)
   One of various species of fishes of the genus {Clupea}, and
   allied genera, esp. the common round or English herring ({C.
   harengus}) of the North Atlantic. Herrings move in vast
   schools, coming in spring to the shores of Europe and
   America, where they are salted and smoked in great
   quantities.

   {Herring gull} (Zo["o]l.), a large gull which feeds in part
      upon herrings; esp., {Larus argentatus} in America, and
      {L. cachinnans} in England. See {Gull}.

   {Herring hog} (Zo["o]l.), the common porpoise.

   {King of the herrings}. (Zo["o]l.)
   (a) The chim[ae]ra ({C. monstrosa}) which follows the schools
       of herring. See {Chim[ae]ra}.
   (b) The opah.

Source : WordNet®

herring hog
     n : the common porpoise of the northern Atlantic and Pacific
         [syn: {harbor porpoise}, {Phocaena phocaena}]