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