Accustomed to being exploited (4)
I believe the answer is:
used
This clue is a double definition.
'accustomed' is the first definition.
(I've seen this in other clues)
'being exploited' is the second definition.
('used' can be a synonym of 'exploited')
'to' is the link.
(Other definitions for used that I've seen before include "not got directly" , "Not fresh" , "Second-hand; exploited" , "Accustomed - exploited" , "exhausted" .)