Town converted Asiatic left for the church (14)
I believe the answer is:
ecclesiastical
'the church' is the definition.
(I've seen this before)
'town converted asiatic left' is the wordplay.
'town' becomes 'eccles' (I have seen 'northern town' mean 'eccles' so perhaps 'town' could also mean 'eccles').
'converted' indicates an anagram.
'left' becomes 'l' (common abbreviation).
'asiatic' anagrammed gives 'iastica'.
'eccles'+'iastica'+'l'='ECCLESIASTICAL'
'for' acts as a link.
(Other definitions for ecclesiastical that I've seen before include "Clergy's" , "Relating to the Christian church" , "Belonging to the church" , "Of the church or clergy" .)