Concealed rifleman (6)
I believe the answer is:
sniper
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">concealed rifleman</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for sniper that I've seen before include "Critic" , "Concealed sharpshooter" , "Hidden gunman" , "Single marksman in concealed place" , "Marksman in hiding place" .)