archdiocese
/ˈɑrkdaɪˌoʊsɪs/Definitions
1. noun
The chief diocese of an ecclesiastical province, ranking above a diocese in importance and authority.
“The archdiocese was the largest in the country, comprising several smaller dioceses.”
2. noun
A high-ranking administrative division of a church, typically ranking above a diocese.
“The archdiocese serves as the spiritual leader for the entire region.”