Source : Webster's Revised Unabridged Dictionary (1913)

Frostfish \Frost`fish"\, n. (Zo["o]l.)
   (a) The tomcod; -- so called because it is abundant on the
       New England coast in autumn at about the commencement of
       frost. See {Tomcod}.
   (b) The smelt. [Local, U. S.]
   (c) A name applied in New Zealand to the scabbard fish
       ({Lepidotus}) valued as a food fish.