Bag in Kinshasa customs (3)
I believe the answer is:
sac
'bag' is the definition.
(a small bag)
'in kinshasa customs' is the wordplay.
'in' indicates a hidden word.
'SAC' can be found hidden inside 'kinshasa customs'.
(Other definitions for sac that I've seen before include "Bodily pouch" , "Bag-like cavity" , "Animal or vegetable pouch" , "Distended membrane; pouch-like cavity" , "Traditional entitlement to hold court" .)