Feudal retainer (6)
I believe the answer is:
vassal
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">feudal retainer</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 vassal that I've seen before include "Feudal underling" , "A humble servant as of 9 Down" , "One owing fealty" , "Feudal subordinate" , "Slave" .)