cetacean - of, relating to, or belonging to Cetacea, an order of aquatic placental mammals having no hind limbs and a blowhole for breathing: includes toothed whales (dolphins, porpoises, etc.) and whalebone whales (rorquals, right whales etc.), species - any of the taxonomic groups into which a genus is divided; often containing subspecies, varieties, or races. Abbrev. sp., kalataolise kehaga täiesti vee-eluviisiga pärisimetajate selts