Any of several gregarious toothed whales of the genus Phocaena and related genera, of oceanic waters, characteristically having a blunt snout and a triangular dorsal fin. Also called sea hog.
Any of several related aquatic mammals, such as the dolphin.
[Middle 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).]