Fairy godmother finally admitted to malice (6)
I believe the answer is:
sprite
'fairy' is the definition.
('sprite' can be a synonym of 'fairy')
'godmother finally admitted to malice' is the wordplay.
'finally' suggests the final letters.
'admitted to' means one lot of letters goes inside another.
'malice' becomes 'spite' (spite is a kind of malice).
The final letter of 'godmother' is 'r'.
'r' inserted within 'spite' is 'SPRITE'.
(Other definitions for sprite that I've seen before include "Supernatural being" , "sports car" , "Naiad" , "A fairy or goblin" , "Small, playful fairy" .)