Fee paid for a servant (8)
I believe the answer is:
retainer
I believe this clue is a double definition.
'fee paid' is the first definition.
(fee paid to retain someone's services)
'for a servant' is the second definition.
('retainer' can be a synonym of 'servant')
(Other definitions for retainer that I've seen before include "Long-standing family servant" , "Fee paid for first option - old family servant" , "Fee; long-term servant" , "Long-serving member of staff" , "reduced rent" .)