Type of large monkey (6)
I believe the answer is:
baboon
'type of large monkey' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for baboon that I've seen before include "A large one of 17 across" , "Type of large monkey" , "Stupid person" , "Ground-living primate" , "clumsy uncouth person" .)