Schism

The word schism is derived from the Greek σχισμα, schisma, meaning division or split (from σχιζο, schizo, "to split").

Schism can refer to:

The offense of inciting divisions among Christians.
The event of two groups of Christians ceasing to be in communion with each other, so that, whereas they formerly could worship together, they decide they must worship separately because of disagreements between them.
The Great Schism; either of two rifts within the Christian church.
Any Christian communion or sect that has left the One Holy Catholic and Apostolic Church. Which church is the One Holy Catholic and Apostolic Church is disputed; the Roman Catholic Church claims that title and considers the Eastern Orthodox Chuch to be a schism; the Eastern Orthodox Church also claims that title and holds that the Roman Catholic church is schismatic.
Any division of a formerly united movement in politics or any other field into two or more disagreeing groups.
The Schism between the anarchistss (libertarian socialistss) and communistss of the International Working Mens' Association; more specifically between their respective leaders: Mikhail Bakunin and Karl Marx.

A schismatic is someone who creates or incites schism or a member of a schismatic church. Schismatic can also be used as an adjective to describe ideas, policies, etc. that are thought to lead towards or promote schism, or to describe a Christian church that has departed from whichever communion the user of the word schism considers the true Christian church.

In the early centuries of Christianity, schism was considered by many Christians to be as serious or more serious than heresy.

Schism is also a song by the band Tool, from the album Lateralus.