"Fiddling" Roman emperor (4)
I believe the answer is:
nero
'fiddling roman emperor' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nero that I've seen before include "Emperor who played the fiddle" , "Fiddling Roman emperor" , "Roman arsonist and fiddler" , "Cruel Roman emperor" , "He's reputed to have fiddled while Rome burned" .)