The ring Winnie returned (4)
I believe the answer is:
hoop
'the ring' is the definition.
('hoop' can be a synonym of 'ring')
'winnie returned' is the wordplay.
'winnie' becomes 'pooh' (I've seen this in another clue).
'returned' says the letters should be written backwards.
'pooh' reversed gives 'HOOP'.
(Other definitions for hoop that I've seen before include "Circle, ring" , "Circle of wood etc" , "Circular band; child's toy" , "Croquet target" , "round during dance" .)