Avid sort of performer (4)
I believe the answer is:
diva
'performer' is the definition.
(diva is a kind of performer)
'avid sort' is the wordplay.
'sort' indicates anagramming the letters.
'avid' with letters rearranged gives 'DIVA'.
'of' acts as a link.
(Other definitions for diva that I've seen before include "Callas, say" , "One who sings" , "Celebrated female operatic star" , "For example Sutherland" , "Prima dona" .)