- any of a family (Phocoenidae) of small, usually gregarious toothed whales found in most seas, with a torpedo-shaped body and a blunt snout
- a dolphin or any of several small whales
Origin of porpoiseMiddle English porpoys ; from Old French porpeis, literally , swine fish ; from Classical Latin porcus, pig (see farrow) + piscis, fish
nounpl. porpoise or por·pois·es
- Any of various marine toothed whales of the genus Phocoena and related genera, characteristically having a blunt snout and a triangular dorsal fin. Porpoises are placed either in their own family, Phocoenidae, or with the dolphins in the family Delphinidae.
- Any of several related aquatic mammals, such as the dolphins.
Origin of porpoiseMiddle English porpeis, from Old French (probably translation of a Germanic compound meaning sea-pig) : porc, pig (from Latin porcus; see porko- in Indo-European roots) + peis, fish (from Latin piscis).
(third-person singular simple present porpoises, present participle porpoising, simple past and past participle porpoised)
- (intransitive) Said of an aircraft: to make a series of plunges when taking off or landing.
From Middle English porpeys, purpeys, from Anglo-Norman porpeis, purpeis, Old French pourpois, pourpais, porpeis (“porpoise"), from Vulgar Latin *porcopiscis (“porpoise", literally “pig-fish"), from Latin porcus (“pig") + piscis (“fish"). Compare (in transposed order) obsolete Italian pesce porco and Portuguese peixe porco; also Latin porcus marinus (“sea hog"), akin in formation to German Meerschwein, English mereswine. More at mereswine.