Top island (6)
I believe the answer is:
jersey
I believe this is a double definition.
'top' is the first definition.
(item of clothing)
'island' is the second definition.
(I've seen this before)
(Other definitions for jersey that I've seen before include "producer for farming programme?" , "Channel Island - jumper" , "Jumper or top" , "whose yellow variety represents the cream" , "Garment - cow - island" .)