Port that's put in a sherry bottle? (4)
I believe the answer is:
cork
I believe this is a double definition.
'port' is the first definition.
(I've seen this before)
'that's put in a sherry bottle?' is the second definition.
(Other definitions for cork that I've seen before include "Tree used in bottling" , "Stopper; Irish city" , "Bark used for floats and stoppers" , "It's needed for a bottle of wine" , "Irish city or county" .)