Advance fee (8)
I believe the answer is:
retainer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">advance fee</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for retainer that I've seen before include "Fee could be the answer" , "Old servant - fee paid in advance" , "Long-serving member of staff" , "Family servant; barrister's fee" , "Down-payment for Eritrean" .)