Fiddling emperor (4)
I believe the answer is:
nero
'fiddling emperor' is the definition.
(emperor who supposedly fiddled as Rome burned)
This is all the clue.
(Other definitions for nero that I've seen before include "Roman tyrant" , "Matricidal emperor" , "He's reputed to have fiddled while Rome burned" , "Famous fiddler" , "Notorious Roman emperor, d. AD 68" .)