Islamic chieftain (4)
I believe the answer is:
emir
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">islamic chieftain</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 emir that I've seen before include "Eastern title" , "Arabic ruler" , "Eastern ruler in mire" , "leader in the East" , "Leading role" .)