coadjutor bishop
A coadjutor bishop (or bishop coadjutor) is a bishop in the Roman Catholic or Anglican churches who is designated to assist the diocesan bishop in the administration of the diocese, almost as co-bishop of the diocese. The coadjutor (literally, "co-assister" in Latin) is a bishop himself and is given authority even beyond that ordinarily given to the vicar-general (although a coadjutor is also appointed a vicar-general), making him co-ruler of the diocese in all but ceremonial precedence.