Band guarded by Samoa's islanders (5)
I believe the answer is:
oasis
'band' is the definition.
(British band)
'guarded by samoa's islanders' is the wordplay.
'guarded by' indicates a hidden word.
'OASIS' is hidden within 'samoas islanders'.
(Other definitions for oasis that I've seen before include "provides refuge" , "Place of calm in troubled times" , "Desert sanctuary" , "Fertile part of desert" , "can provide welcome relief" .)