Refinement of holy woman going round a church (6)
I believe the answer is:
nuance
'refinement' is the definition.
(I know that refinement can be written as nuance)
'holy woman going round a church' is the wordplay.
'holy woman' becomes 'nun' (woman who has taken religious vows).
'going round' means one lot of letters goes inside another (some letters go around others).
'church' becomes 'CE' (abbreviation for Church of England).
'nun' going around 'a' is 'nuan'.
'nuan'+'ce'='NUANCE'
'of' is the link.
(Other definitions for nuance that I've seen before include "A hint or shade" , "Subtle distinction or variation" , "Subtle shade of meaning" , "Delicate shade of meaning" , "Fine distinction" .)