Fulfilled expert (12)
I believe the answer is:
accomplished
This clue is a double definition.
'fulfilled' is the first definition.
('accomplish' can be a synonym of 'fulfil')
'expert' is the second definition.
(synonyms)
(Other definitions for accomplished that I've seen before include "Highly skilled" , "executed" , "Achieved success" , "Done - with a high degree of skill" , "Talented - performed" .)