cetacean
Concise Oxford English Dictionary © 2008 Oxford University Press:
cetacean /sɪˈteɪʃən/ Zoology
▶noun a marine mammal of the order Cetacea; a whale, dolphin, or porpoise. ▶adjective relating to the cetaceans.
– origin from mod. L. Cetacea, from L. cetus, from Gk kētos ‘whale’.
'cetacean' also found in these Oxford entries:

