County; stopper (4)
I believe the answer is:
cork
I believe this is a double definition.
'county' is the first definition.
(county of Ireland)
'stopper' is the second definition.
(I know that stopper can be written as cork)
(Other definitions for cork that I've seen before include "Irish seaport" , "A tree; a stopper" , "One stops" , "Stopper - Irish port" , "Bottle-stopper for a southern city" .)