Gibbons and gorillas (4)
I believe the answer is:
apes
'gibbons and gorillas' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for apes that I've seen before include "Parrots" , "Imitates in every aspect" , "Mimics like primates" , "Copies the primates?" , "Zoo animals" .)