Nuance in tiny changes around church (6)
I believe the answer is:
nicety
'nuance' is the definition.
(synonyms)
'tiny changes around church' is the wordplay.
'changes' indicates an anagram.
'around' means one lot of letters goes inside another.
'church' becomes 'CE' (abbreviation for Church of England).
'tiny' is an anagram of 'nity'.
'nity' enclosing 'ce' is 'NICETY'.
'in' acts as a link.
(Other definitions for nicety that I've seen before include "Nuance - icy net (anag)" , "A detail of etiquette" , "Matter of delicate adjustment" , "Judge to a . . . . . . - with precision" , "Fine distinction" .)