Friendly native, Harry, not retiring (6)
I believe the answer is:
tongan
'friendly native' is the definition.
(native of Tonga (known as the 'Friendly Islands'))
'harry not retiring' is the wordplay.
'harry' becomes 'nag' ('harry' can mean 'to persistently bother').
'retiring' shows that the letters should be reversed in order.
'nag'+'not'='nagnot'
'nagnot' in reverse letter order is 'TONGAN'.
(Other definitions for tongan that I've seen before include "Friendly Islander" , "One from the Friendly Islands, as was" , "Language" .)