porpoise

[ pawr-puh s ]
/ ˈpɔr pəs /

noun, plural (especially collectively) por·poise, (especially referring to two or more kinds or species) por·pois·es.

any of several small, gregarious cetaceans of the genus Phocoena, usually blackish above and paler beneath, and having a blunt, rounded snout, especially the common porpoise, P. phocoena, of both the North Atlantic and Pacific.
any of several other small cetaceans, as the common dolphin, Delphinus delphis.

verb (used without object), por·poised, por·pois·ing.

(of a speeding motorboat) to leap clear of the water after striking a wave.
(of a torpedo) to appear above the surface of the water.
to move forward with a rising and falling motion in the manner of a porpoise: The car has a tendency to porpoise when overloaded.

Origin of porpoise

1275–1325; Middle English porpoys < Middle French porpois < Vulgar Latin *porcopiscis hog fish, for Latin porcus marīnus sea hog

OTHER WORDS FROM porpoise

por·poise·like, adjective

British Dictionary definitions for porpoising

porpoise
/ (ˈpɔːpəs) /

noun plural -poises or -poise

any of various small cetacean mammals of the genus Phocaena and related genera, having a blunt snout and many teeth: family Delphinidae (or Phocaenidae)
(not in technical use) any of various related cetaceans, esp the dolphin

Word Origin for porpoise

C14: from French pourpois, from Medieval Latin porcopiscus (from Latin porcus pig + piscis fish), replacing Latin porcus marīnus sea pig