One of five types of disciplinary acts meted out by the saṅgha. A monk may be expelled on one of seven grounds: failing to acknowledge a fault; refusing to amend or rehabilitate one’s behavior; refusing to relinquish deviant views; being overly belligerent and quarrelsome; creating the circumstances for a quarrel; maintaining overly close relations with nuns, unruly people, or malingerers; and refusing to let go of a dharma matter that has been peacefully resolved.