Unambiguous article on church will get authorization (9)
I believe the answer is:
clearance
'authorization' is the definition.
(clearance is a kind of authorization)
'unambiguous article on church' is the wordplay.
'unambiguous' becomes 'clear' ('clear' is associated in meaning with 'unambiguous').
'article' becomes 'an' (indefinite article).
'on' is a charade indicator (letters next to each other).
'church' becomes 'ce' (abbreviation for Church of England).
'clear'+'an'+'ce'='CLEARANCE'
'will get' acts as a link.
(Other definitions for clearance that I've seen before include "Sanction" , "eviction from land" , "evacuation" , "Permission to proceed" , "eviction of tenants" .)