Callas role (5)
I believe the answer is:
tosca
'callas role' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tosca that I've seen before include "One of Puccini's 19" , "Puccini heroine" , "Puccini's jumper" , "celebrated singer" , "Luigi -, Italian playwright" .)