Fee for a servant (8)
I believe the answer is:
retainer
I believe this clue is a double definition.
'fee' is the first definition.
(retainer is a kind of fee)
'servant' is the second definition.
(synonyms)
'for a' is the link.
(Other definitions for retainer that I've seen before include "Fee paid to book professional services" , "Faithful old servant - maybe Eritrean" , "Down-payment for Eritrean" , "Part payment down for an old servant" , "money to be paid in advance" .)