Gorilla or chimpanzee (3)
I believe the answer is:
ape
This clue is a double definition.
'gorilla' is the first definition.
(gorillas are apes)
'chimpanzee' is the second definition.
(chimpanzees are apes)
(Other definitions for ape that I've seen before include "Imitate, clumsy person (colloq.)" , "drill" , "intelligent creature" , "Take off" , "Idiot" .)