Person of action (4)
I believe the answer is:
doer
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">person of action</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for doer that I've seen before include "energetic person?" , "agent" , "Martha?" , "Person who acts" , "Person of action" .)