Co-adjutor

A coadjutor bishop (or bishop coadjutor) is a bishop in the Roman Catholic, Anglican, and (historically) Eastern Orthodox churches who is designated to assist the diocesan bishop in the administration of the diocese. The coadjutor (literally, "co-assister" in Latin) is a bishop himself. While also appointed as vicar general, the coadjutor bishop is given authority beyond that ordinarily given to the vicar general, making him co-head of the diocese in all but ceremonial precedence. In modern times, the coadjutor automatically succeeds the current bishop of a diocese upon the latter's retirement, removal, or death.

In the Roman Catholic Church, a coadjutor bishop is an immediate collaborator of the diocesan bishop, similar to an auxiliary bishop. Unlike auxiliary bishops, coadjutors are given the right of succession to the episcopal see. When the diocesan bishop dies, retires, resigns, or is reassigned, the coadjutor automatically becomes the next bishop of the local Church (diocese). Until then, the diocesan bishop appoints the coadjutor to act as vicar general. He needs to be ordained and generally holds a titular see until his succession.

In modern church practice, the appointment of a coadjutor is usually done in cases where a diocesan bishop feels that he will not be able to continue in his position for health reasons or impending retirement. In these cases, the Pope may assign a coadjutor in order to give him time to become familiar with the diocese that he will eventually take over. For example, Bishop Dennis Marion Schnurr of the Diocese of Duluth, Minnesota, was named Coadjutor Archbishop of the Archdiocese of Cincinnati, Ohio, in 2008 to succeed aging Archbishop Daniel Edward Pilarczyk.

...
Wikipedia