Singer eager to make a comeback? (4)
I believe the answer is:
diva
'singer' is the definition.
(diva is a kind of singer)
'eager to make a comeback?' is the wordplay.
'eager' becomes 'avid' ('avid' can be a synonym of 'eager').
'to make a comeback?' is a reversal indicator (I've seen 'making a comeback' mean this).
'avid' backwards is 'DIVA'.
(Other definitions for diva that I've seen before include "Distinguished female singer" , "Great performer" , "Prima donna, woman opera singer" , "Famous female singer" , "A female opera singer" .)