Genghis or Kublai (4)
I believe the answer is:
khan
'genghis or kublai' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for khan that I've seen before include "Persian governor" , "Imran --, Pakistan's PM" , "Title of respect in central Asia (for a descendant of Genghis?)" , "Central Asian prince or chief" , "Title taken by ancient Mongol emperors, such as Genghis" .)