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.
porpoise (plural porpoises)
- A small cetacean of the family Phocoenidae, related to whales and dolphins.
- (North America, imprecisely) Any small dolphin.
- (intransitive) Said of an aircraft: to make a series of plunges when taking off or landing.