City of the Ruhr
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">city of the ruhr</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 essen that I've seen before include "German industrial centre" , "German industrial city on the Ruhr" , "Industrial city of northwest Germany" , "European city" , "Krupp HQ (Ger.)" .)