noun
diocese
A Christian ecclesiastical district under the jurisdiction of a bishop. Used in Catholic, Orthodox, and Anglican contexts.
この司教区には多くの教会がある。
There are many churches in this diocese.
大司教区 is an archdiocese, a larger or more important diocese headed by an archbishop.
Compound of 司教 (bishop) and 区 (district, ward). The term is a modern translation of the Christian concept of a diocese.