South Pacific island group (5)
I believe the answer is:
samoa
'south pacific island group' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for samoa that I've seen before include "Pacific islands state" , "Commonwealth country in the Pacific, capital Apia" , "Pacific island nation, capital Apia" , "Polynesian isle" , "Polynesian island group" .)