An opera by Puccini (5)
I believe the answer is:
tosca
'an opera by puccini' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tosca that I've seen before include "Opera heroine who leaps to her death" , "Puccini heroine" , "18 [OPERA]" , "Leaping opera heroine" , "Photographic device" .)