Distinguished singer keen to come up (4)
I believe the answer is:
diva
'distinguished singer' is the definition.
'diva' can be an answer for 'singer' (diva can mean a female opera singer). I'm unsure of the 'distinguished' bit.
'keen to come up' is the wordplay.
'keen' becomes 'avid' (both can mean enthusiastic).
'to come up' says the letters should be written backwards.
'avid' in reverse letter order is 'DIVA'.
Can you help me to learn more?
(Other definitions for diva that I've seen before include "High-maintenace woman" , "Famous female singer" , "Callas, say" , "fat lady?" , "Prima dona" .)