schism
n
1 the division of a group into opposing factions
3 division within or separation from an established Church, esp. the Roman Catholic Church, not necessarily involving differences in doctrine (C14: from Church Latin schisma, from Greek skhisma a cleft, from skhizein to split)
Great Schism
n
1 the breach between the Eastern and Western churches, usually dated from 1054
2 the division within the Roman Catholic Church from 1378 to 1429, during which rival popes reigned at Rome and Avignon