A judge returned after port wine (5)
I believe the answer is:
rioja
'wine' is the definition.
(Rioja is an example)
'a judge returned after port' is the wordplay.
'judge' becomes 'j'.
'returned' says the letters should be written backwards.
'after' says to put letters next to each other.
'port' becomes 'rio' (I've seen this before).
'a'+'j'='aj'
'aj' in reverse letter order is 'ja'.
'ja' after 'rio' is 'RIOJA'.
(Other definitions for rioja that I've seen before include "North Spanish wine" , "Popular Spanish wine" , "Spanish wine type" , "Spanish drink" , "Open space (ancient Greek)" .)