Reduce in rank (6)
I believe the answer is:
demote
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">reduce in rank</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 demote that I've seen before include "Move down in rank" , "Relegate" , "Put down in rank" , "Reduce to lower rank as punishment" , "Move to lower status" .)