Leaving medal hanging around middle of stick (5)
I believe the answer is:
going
'leaving' is the definition.
(I know that leaving can be written as going)
'medal hanging around middle of stick' is the wordplay.
'medal' becomes 'gong' (informal term for a medal or prize).
'hanging around' indicates putting letters inside.
'middle of' means to look at the middle letters.
The middle of 'stick' is 'i'.
'gong' going around 'i' is 'GOING'.
(Other definitions for going that I've seen before include "factor in horse's performance?" , "Ground condition for horse racing" , "Running; leaving" , "attending" , "Due to leave" .)