An animal belonging to the order Cetacea, including dolphins, porpoises, and whales.
The tour promised spiritual experiences with humpback whales and other cetaceans, but all we saw were seagulls and a dead sea otter.
Pertaining to the zoologic order Cetacea, or associated with species falling under that taxonomic hierarchy.
The poached blubber was definitely cetacean in origin, but the particular species could not be identified.
(by extension, sometimes figurative) Resembling or relating to large aquatic mammals.
The obese woman, ungainly on land, moved with a kind of cetacean grace in the water.