The Collaborative International Dictionary of English v.0.48:

Tomcod \Tom"cod`\ (t[o^]m"k[o^]d`), n. [Tom (see Tomboy) +
   cod: cf. F. tacaud whiting pout, American Indian tacaud,
   literally, plenty fish.] (Zool.)
   (a) A small edible American fish (Microgadus tomcod) of the
       Codfish family, very abundant in autumn on the Atlantic
       coast of the Northen United States; -- called also
       frostfish. See Illust. under Frostfish.
   (b) The kingfish. See Kingfish
   (a) .
   (c) The jack. See 2d Jack, 8.
   (c) .
       [1913 Webster]