Oscar, upset by a bit of mildew? (5)
I believe the answer is:
wilde
'oscar' is the definition.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for wilde that I've seen before include "Oscar --, playwright, wit and author" , "Oscar --, English writer" , "Author of The Picture of Dorian Gray" , "Oscar -, Irish author" , "Author of The Portrait of Dorian Gray" .)