Pawn – white wine (4)
I believe the answer is:
hock
I believe this clue is a double definition.
'pawn' is the first definition.
(hock can mean to pawn an item at a pawnbroker's)
'white wine' is the second definition.
(hock is a kind of white wine)
(Other definitions for hock that I've seen before include "Pawn a German wine?" , "Animal joint - German white wine" , "Dry wine; joint; pawn" , "A wine; part of horse's leg" , "Uncle's pledge" .)