Cetacea
Pronunciation: /sɪˈteɪʃə/
plural noun
Zoology- an order of marine mammals that comprises the whales, dolphins, and porpoises. These have a streamlined hairless body, no hindlimbs, a horizontal tail fin, and a blowhole on top of the head for breathing. See also Mysticeti, Odontoceti.
Origin:
modern Latin (plural), from Latin cetus, from Greek kētos 'whale'