German emperor (6)
I believe the answer is:
kaiser
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">german emperor</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for kaiser that I've seen before include "Former German emperor" , "Ruler over empire" , "Ex-ruler of Germany" , "Austrian bigwig" , "Old German emperor like Bill" .)