/ Dictionary / Index C cetacean: Meaning and Definition of Find definitions for: ce•ta•cean Pronunciation: (si-tā'shun), [key] — adj. belonging to the Cetacea, an order of aquatic, chiefly marine mammals, including the whales and dolphins. —n. a cetacean mammal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: cetacean (Thesaurus) CETA cetaceum Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language