See church included in OED is corrupt (7)
I believe the answer is:
diocese
'see' is the definition.
(both can mean a bishop's associated area)
'church included in oed is corrupt' is the wordplay.
'church' becomes 'CE' (abbreviation for Church of England).
'included in' is an insertion indicator.
'corrupt' is an anagram indicator (a corrupted spelling of the word).
'oed'+'is'='oedis'
'oedis' is an anagram of 'diose'.
'ce' put inside 'diose' is 'DIOCESE'.
(Other definitions for diocese that I've seen before include "Bishop's area" , "Bishop's responsibility" , "District under a bishop's jurisdiction" , "Bishop's region" , "Area under bishop" .)