Western missing out on Oscar after head of Academy noted exception (10)
I believe the answer is:
accidental
'western' is the definition.
Both the definition and answer are adjectives. Perhaps there's a link between them I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for accidental that I've seen before include "Sign raising or lowering a musical note" , "without planning" , "Subsidiary" , "Happening by chance" , "Possible sharp" .)