Source : Webster's Revised Unabridged Dictionary (1913)

Cetacean \Ce*ta"cean\, n. (Zo["o]l.)
   One of the Cetacea.

Source : WordNet®

cetacean
     adj : of or relating to whales and dolphins etc [syn: {cetaceous}]

cetacean
     n : large aquatic carnivorous mammal with fin-like forelimbs no
         hind limbs, including: whales; dolphins; porpoises;
         narwhals [syn: {cetacean mammal}, {blower}]