"Das Kapital" author (4)
I believe the answer is:
marx
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">das kapital author</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for marx that I've seen before include "Groucho's surname" , "Karl, top communist" , "Das Kapital author" , "Communist founder" , "Founder of communism" .)