South Pacific archipelago (4)
I believe the answer is:
fiji
'south pacific archipelago' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for fiji that I've seen before include "Pacific island state" , "Pacific island nation, capital Suva" , "South Pacific country of some 840 islands" , "Southwest Pacific republic made up of 844 islands" , "Pacific island member of the Commonwealth, capital Suva" .)