Old post game judge turned down (7)
I believe the answer is:
refused
'turned down' is the definition.
('refuse' can be a synonym of 'turn down')
'old post game judge' is the wordplay.
'old' becomes 'used' (as in used or second-hand items).
'post' says to put letters next to each other (post- can mean after).
'game judge' becomes 'ref' (referee. I am not sure about the 'game' bit.).
'used' put after 'ref' is 'REFUSED'.
Can you help me to learn more?
(Other definitions for refused that I've seen before include "Was unwilling to accept" , "Declined, rejected" , "Not accepted" , "Said no (7)" , "turned down appeal" .)