A porpoise is a sea animal that looks like a large grey fish. Porpoises usually swim about in groups.
porpoise in British English
(ˈpɔːpəs)
nounWord forms: plural-poises or -poise
1.
any of various small cetacean mammals of the genus Phocaena and related genera, having a blunt snout and many teeth: family Delphinidae (or Phocaenidae)
2. (not in technical use)
any of various related cetaceans, esp the dolphin
Word origin
C14: from French pourpois, from Medieval Latin porcopiscus (from Latin porcus pig + piscis fish), replacing Latin porcus marīnus sea pig
porpoise in American English
(ˈpɔrpəs)
nounWord forms: pluralˈporpoises or ˈporpoise
1.
any of a family (Phocoenidae) of small, usually gregarious toothed whales found in most seas, with a torpedo-shaped body and a blunt snout
2.
a dolphin or any of several small whales
Word origin
ME porpoys < OFr porpeis, lit., swine fish < L porcus, pig (see farrow1) + piscis, fish