Excellent prize kitty picked up (3-6)
I believe the answer is:
top-drawer
'excellent' is the definition.
(I know that excellent can be written as top-drawer)
'prize kitty picked up' is the wordplay.
'prize' becomes 'reward' (a prize may be given as a reward).
'kitty' becomes 'pot' (both can mean a shared fund).
'picked up' shows that the letters should be reversed in order.
'reward'+'pot'='rewardpot'
'rewardpot' reversed gives 'TOP-DRAWER'.
(Other definitions for top-drawer that I've seen before include "Perfect" , "Excellent" , "Of the highest standing" , "of high social standing" .)