Yours, Etc.: Origins and Uses of 8 Sign-Offs
1590s, earlier graundepose (1520s), altered (by influence of grand) from Middle English graspeys (late 13c.), from Anglo-French grampais, from Old French graspois, craspois "whale, (salted) whale meat; blubber; seal," from Medieval Latin craspicis, literally "fat fish," from Latin crassus "thick" + piscis "fish." For specifics of usage in English, see OED.
a common offshore inhabitant of tropical and temperate ocean waters, a member of the dolphin family (Delphinidae). The grampus measures about 4 metres (approximately 13 feet) in length and has a blunt head and a distinct longitudinal forehead crease. It is unique among dolphins in usually having no upper teeth and from zero to seven teeth in the lower jaw. Older males are heavily scarred about the head and trunk, apparently owing to encounters with other grampuses.