Tried small, sufficient diamonds (7)
I believe the answer is:
sampled
'tried' is the definition.
('sample' can be a synonym of 'try')
'small sufficient diamonds' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'sufficient' becomes 'ample' (both can mean enough).
'diamonds' becomes 'd' (abbreviation in bridge say).
's'+'ample'+'d'='SAMPLED'
(Other definitions for sampled that I've seen before include "Tasted" , "tried" .)