Wine left on board (4)
I believe the answer is:
port
I believe this is a double definition.
'wine' is the first definition.
(port is a kind of wine)
'left on board' is the second definition.
(port is left on board a ship)
(Other definitions for port that I've seen before include "Harbour; alcoholic drink" , "Drink passed to the left" , "Anchorage" , "Rio, perhaps" , "Left side of ship - red wine" .)