Unpretentiousness taken for granted in outskirts of Salisbury (10)
I believe the answer is:
simplicity
'unpretentiousness' is the definition.
(thesaurus)
'taken for granted in outskirts of salisbury' is the wordplay.
'taken for granted' becomes 'implicit' (I've seen this before).
'in' means one lot of letters goes inside another.
'outskirts of' means to remove the middle letters.
'salisbury' with its centre taken out is 'sy'.
'implicit' put within 'sy' is 'SIMPLICITY'.
(Other definitions for simplicity that I've seen before include "Lack of affectation or pretence" , "Clarity" , "Ease" , "Couldn't be easier!" , "Facility, easiness" .)