Sea cow (7)
'sea cow' is the definition.
(manatee is a kind of sea cow)
This is the entire clue.
(Other definitions for manatee that I've seen before include "big creature" , "rare sea mammal" , "water animal" , "Large aquatic mammal -- sea cow" , "Sea denizen" .)
'sea cow' is the definition.
(species of sea cow)
This is all the clue.
(Other definitions for dugong that I've seen before include "Sea cow - gun dog (anag)" , "Sea cow with forked tail" , "Marine creature" , "Sea beast" , "Marine mammal" .)