Purity bar formerly including church (9)
I believe the answer is:
innocence
'purity' is the definition.
(I know that purity can be written as innocence)
'bar formerly including church' is the wordplay.
'bar' becomes 'inn' (both can mean a drinking establishment).
'formerly' becomes 'once' (synonyms).
'including' is an insertion indicator.
'church' becomes 'CE' (Church of England).
'once' going around 'ce' is 'ocence'.
'inn'+'ocence'='INNOCENCE'
(Other definitions for innocence that I've seen before include "Freedom from guilt" , "Guilelessness" , "''Songs of ... and Experience'' (William Blake)" , "Uncorrupted state" , "Blamelessness" .)