White wine in bag (4)
I believe the answer is:
sack
I believe this is a double definition.
'white wine' is the first definition.
(sack is a kind of white wine)
'bag' is the second definition.
(sack is a kind of bag)
'in' acts as a link.
(Other definitions for sack that I've seen before include "Get rid of" , "Fire - plunder and destroy" , "boot" , "Plunder; wine; bag" , "Large canvas bag" .)