Disapproving gossip about fellow drama queen (5,5)
I believe the answer is:
prima donna
'drama queen' is the definition.
(I've seen this before)
'disapproving gossip about fellow' is the wordplay.
'disapproving' becomes 'prim'.
'gossip' becomes 'ana' (I have seen 'literary gossip' mean 'ana' so perhaps 'gossip' could also mean 'ana').
'about' means one lot of letters goes inside another.
'fellow' becomes 'don' (I've seen this before).
'ana' going around 'don' is 'adonna'.
'prim'+'adonna'='PRIMA DONNA'
(Other definitions for prima donna that I've seen before include "Very self-important person" , "drama queen" , "(Over-sensitive) leading lady" , "temperamental sort" , "Top female singer" .)