A gentle eccentric -- so refined (7)
I believe the answer is:
elegant
'refined' is the definition.
('elegant' can be a synonym of 'refined')
'a gentle eccentric' is the wordplay.
'eccentric' is an anagram indicator.
'a'+'gentle'='agentle'
'agentle' anagrammed gives 'ELEGANT'.
'so' acts as a link.
(Other definitions for elegant that I've seen before include "luxurious style?" , "Well-turned" , "Attractive and graceful or stylish" , "Graceful - refined" , "Chic; smart" .)