Author of Das Kapital (4)
I believe the answer is:
marx
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">author of das kapital</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 marx that I've seen before include "The Economist" , "Communist or funny brother?" , "Karl, top communist" , "Groucho's surname" , "Second part of 20" .)