diocese
Concise Oxford English Dictionary © 2008 Oxford University Press:
diocese /ˈdʌɪəsɪs/
▶noun (pl. dioceses /ˈdʌɪəsiːz, -siːzɪz/) a district under the pastoral care of a bishop in the Christian Church.
– origin ME: from OFr. diocise, from late L. diocesis, from L. dioecesis ‘governor's jurisdiction, diocese’.
'diocese' also found in these Oxford entries:

