Circular earring
I believe the answer is:
hoop
'circular earring' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for hoop that I've seen before include "Ring of wood - arch at croquet" , "children's toy" , "Circle, ring" , "Circular band; child's toy" , "Wood, metal or plastic band" .)