Suggestion from sister outside a church (6)
I believe the answer is:
nuance
'suggestion' is the definition.
(thesaurus)
'sister outside a church' is the wordplay.
'sister' becomes 'nun' (I've seen this before).
'outside' means one lot of letters goes inside another.
'church' becomes 'ce' (abbreviation for Church of England).
'nun' enclosing 'a' is 'nuan'.
'nuan'+'ce'='NUANCE'
'from' is the link.
(Other definitions for nuance that I've seen before include "A slight shade or trace" , "Subtlety, nicety" , "Slight difference in meaning etc" , "A slight shade as of meaning" , "Subtle difference of meaning" .)