The term "arch-diocese" refers to an administrative division within the Catholic Church. However, there are several synonyms for this term that may be used in different contexts. One such synonym is "metropolitan see," which refers to a diocese that has legal jurisdiction over other dioceses in a particular region. Another synonym is "eparchy," which is a term used in Eastern Catholic and Orthodox churches to refer to a diocese or arch-diocese. In some instances, the term "archbishopric" may be used instead of arch-diocese. Ultimately, each of these terms refers to an administrative division within a church, with its own leader and defined geographical boundaries.