Ruler in ancient Egypt (7)
I believe the answer is:
pharaoh
'ruler in ancient egypt' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pharaoh that I've seen before include "Old Egyptian king" , "Cheops, for example" , "Eg, Tutankhamen" , "Title of ancient Egyptian kings" , "Ancient king of Egypt" .)