Fairy, cast off, died (8)
I believe the answer is:
perished
'died' is the definition.
('perish' can be a synonym of 'die')
'fairy cast off' is the wordplay.
'fairy' becomes 'peri' (Persian mythological being).
'cast off' becomes 'shed' (synonyms).
'peri'+'shed'='PERISHED'
(Other definitions for perished that I've seen before include "Died, failed" , "(Of rubber) forty three" , "dead - with 15a" , "Ruined" , "Extremely cold - died - rotted" .)