The root of the word is "overseer." It refers to a Bishop. It also refers to the Christian denomination, the
Episcopal Church in the United States of America, which is part of the worldwide
Anglican Church with its origins in the Church of England. (In Canada, it is the Anglican Church, in England it is the Church of England, in
Scottland it is the Episcopal Church.) It began when Henry VIII broke off the church in England with the Roman Catholic Church (the Pope in Rome) and declared that the Church of England would be ruled from England, not Rome.