The Collaborative International Dictionary of English v.0.48:

Grampus \Gram"pus\, n.; pl. Grampuses. [Probably corrupted
   from It. gran pesce great fish, or Sp. gran pez, or Pg. gran
   peixe, all fr. L. grandis piscis. See Grand, and Fish.
   the animal.]
   1. (Zool.) A toothed delphinoid cetacean, of the genus
      Grampus, esp. G. griseus of Europe and America, which
      is valued for its oil. It grows to be fifteen to twenty
      feet long; its color is gray with white streaks. Called
      also cowfish. The California grampus is G. Stearnsii.
      [1913 Webster]

   2. A kind of tongs used in a bloomery. [U.S.] Granade

The Collaborative International Dictionary of English v.0.48:

Cowfish \Cow"fish`\ (kou"f[i^]sh`), n. (Zool.)
   (a) The grampus.
   (b) A California dolphin (Tursiops Gillii).
   (c) A marine plectognath fish (Ostracoin quadricorne, and
       allied species), having two projections, like horns, in
       front; -- called also cuckold, coffer fish,
       trunkfish.
       [1913 Webster]

WordNet (r) 3.0 (2006):

cowfish
    n 1: trunkfish having hornlike spines over the eyes [syn:
         cowfish, Lactophrys quadricornis]