Boy king of ancient Egypt (3)
I believe the answer is:
tut
'boy king of ancient egypt' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tut that I've seen before include "Annoyed exclamation" , "I disapprove" , "King exhumed" , "in short I don't like that!" , "Disapproving comment" .)