Ring a jockey (4)
I believe the answer is:
hoop
This could be a double definition.
'ring' is the first definition.
(I know that ring can be written as hoop)
'a jockey' is the second definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
Can you help me to learn more?
(Other definitions for hoop that I've seen before include "Circlet" , "Large ring" , "Wood, metal or plastic band" , "Arch used in croquet" , "Rigid circular band" .)