Gorilla or chimp (3)
I believe the answer is:
ape
I believe this clue is a double definition.
'gorilla' is the first definition.
(I've seen this before)
'chimp' is the second definition.
(thesaurus)
(Other definitions for ape that I've seen before include "Simulate" , "Primate resembling a human" , "Idiot" , "Our cousin" , "Closely follow" .)