A gift provided by volunteers (6)
I believe the answer is:
talent
'a gift' is the definition.
('talent' can be a synonym of 'gift')
'provided by volunteers' is the wordplay.
'provided' becomes 'lent' (I've seen this in other clues).
'by' is a charade indicator (letters next to each other).
'volunteers' becomes 'TA' (abbreviation for Territorial Army).
'lent' after 'ta' is 'TALENT'.
(Other definitions for talent that I've seen before include "some scouts are looking for" , "Natural ability or aptitude" , "Flair, aptitude" , "Unit of currency" , "Special aptitude for the old Greek money" .)