Copper (9)
I believe the answer is:
constable
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">copper</span>' is the definition.<br/ ><span class="explanation-format__explanation">(type of police officer)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for constable that I've seen before include "Force member" , "English landscape painter for a policeman" , "Flatford Mill painter" , "See 1" , "Bobby" .)