Cetacea

['setəsiə]

Cetacea (n.): order of marine mammals containing whales, 1830, Modern Latin, from Latin cetus "any large sea creature" (whales, seals, dolphins), from Greek ketos "a whale, a sea monster," which is of unknown origin, + -acea. Hence cetology "the study of whales," first attested 1851 in "Moby Dick."