grampus

1. A cetacean (Grampus griseus) related to and resembling the dolphins but lacking a beaklike snout.
2. Any of various similar cetaceans, such as the killer whale.

[Alteration (perhaps influenced by GRAND) of Middle English graspeis, from Old French craspois, graspeis, from Medieval Latin crassus piscis, craspiscis : Latin crassus, fat + Latin piscis, fish.]

Killer whale, Orcinus orca. The name is also used for Risso's dolphin, Grampus griseus.

The noun has 2 meanings:

Meaning #1: predatory black-and-white toothed whale with large dorsal fin; common in cold seas
  Synonyms: killer whale, killer, orca, sea wolf, Orcinus orca

Meaning #2: slaty-gray blunt-nosed dolphin common in northern seas
  Synonym: Grampus griseus