Passionate female singer makes a comeback (4)
I believe the answer is:
avid
'passionate' is the definition.
(I've seen this in another clue)
'female singer makes a comeback' is the wordplay.
'female singer' becomes 'diva' (term for a famous opera singer).
'makes a comeback' is a reversal indicator (I've seen 'making a comeback' mean this).
'diva' back-to-front is 'AVID'.
(Other definitions for avid that I've seen before include "Fanatical" , "Showing a very keen interest in something" , "Eager like diva" , "Very keen, desirous" , "Zealous, enthusiastic" .)