Island garment (6)
I believe the answer is:
jersey
I believe this clue is a double definition.
'island' is the first definition.
(I've seen this before)
'garment' is the second definition.
(I know that jersey is a type of shirt)
(Other definitions for jersey that I've seen before include "Cyclist's shirt" , "Milked" , "Largest of the Channel Islands" , "producer for farming programme?" , "One over the moon might have been such" .)