Diva's delight (4)
I believe the answer is:
'diva's delight' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for aria that I've seen before include "Operatic tune" , "Operatic solo performance" , "Summertime perhaps" , "Operatic number" , "Vocal solo in a cantata etc" .)