Main Entry: ce·ta·cean

Pronunciation: \si-ˈtā-shən\

Function: noun

Etymology: ultimately from Latin cetus whale, from Greek kētos

Date: 1835

: any of an order (Cetacea) of aquatic mostly marine mammals that includes the whales, dolphins, porpoises, and related forms and that have a torpedo-shaped nearly hairless body, paddle-shaped forelimbs but no hind limbs, one or two nares opening externally at the top of the head, and a horizontally flattened tail used for locomotion

— cetacean adjective

— ce·ta·ceous \-shəs\ adjective