From Longman Dictionary of Contemporary Englishcetaceance‧tac‧ean /sɪˈteɪʃən/ noun [countable] HBA technical a mammal that lives in the sea, such as a whale —cetacean adjective
Examples from the Corpus
cetacean• Sound production and hearing in the Bottle-nosed dolphin had been studied more than those of any other cetacean.• Public concern over the popular cetacean has mounted as numbers have rapidly declined.• The biggest danger for any stranded cetacean is overheating.Origin cetacean (1800-1900) Latin cetus “whale”, from Greek ketos 