Star from another opera (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
hero
'star' is the definition.
(I've seen this before)
'from another opera' is the wordplay.
'from' says the answer is hidden in the clue.
'HERO' can be found hidden inside 'another opera'.
(Other definitions for hero that I've seen before include "priestess of Aphrodite" , "Lion" , "Very brave man" , "Conqueror" , "victor" .)