South Pacific nation (5)
I believe the answer is:
nauru
'south pacific nation' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nauru that I've seen before include "Smallest Pacific state" , "Pacific island country" , "little nation" , "Pacific republic, formerly Pleasant Island" , "Pacific coral island republic, once rich in phosphates" .)