Meaning

noun any of several small gregarious cetacean mammals having a blunt snout and many teeth

originFrom Middle English porpeys, purpeys, borrowed from Anglo-Norman porpeis, purpeis, Old French pourpois, porpois, pourpais, porpeis (“porpoise”), from Vulgar Latin *porcopiscis (“porpoise”, literally “hog-fish”), taken from Latin porcus (“hog, pig”) + piscis (“fish”). Compare (in transposed order) obsolete Italian pesce porco and Portuguese peixe porco; also Latin porcus marīnus (“sea hog”); akin…

Etymology from Wiktionary, CC BY-SA 3.0