Bishop - In the early church, he was a chief priest at a church. Later, the role became that of a priest with administrative duties over a group of churches within a geographical area called a diocese.

A bishop is an ordained member of the Christian clergy who, in certain Christian churches, holds a position of authority. (wikipedia)

A bishop in The Church of Jesus Christ of Latter-day Saints is a church officer that presides over a ward. He is considered "the father of the ward" and is usually the leader most intimately involved with patrons. The LDS Church operates on a Lay-Ministry where all offices or "callings" are filled by unpaid memebers of the congregation. (wikipedia)

A clergyman having spiritual and administrative authority; appointed in Christian churches to oversee priests or ministers; considered in some churches to be successors of the twelve apostles of Christ.

The Biblical term for the one who exercises pastoral care and authority over a large number of Christians.