Synonyms for Cetacean (same or very similar meaning)
WordNet sense 1 (of or relating to whales and dolphins etc):
cetaceousWordNet sense 2 (large aquatic carnivorous mammal with fin-like forelimbs no hind limbs, including: whales; dolphins; porpoises; narwhals):
blower, cetacean mammalFrom the ODE community, based on WordNetadd/edit