CETACEAN

[ce.ta.cean] n [ultim. fr. L cetus whale, fr. Gk ketos] (1836): any of an order (Cetacea) of aquatic mostly marine mammals that include 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 adj -- ce.ta.ceous adj