Central Asian ruler (4)
I believe the answer is:
khan
'central asian ruler' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for khan that I've seen before include "Imran --, cricketer" , "Eastern emperor" , "Asian ruler (descendant of Genghis?)" , "A Genghis successor?" , "Central Asian prince or chief" .)