The term 'banish from group' can be summarized by the crossword solution 'OSTRACISE' which is a nine-letter word. Ostracism is the act of excluding someone from a group or society, usually as a form of punishment. It was a common practice in Ancient Greece, where citizens could be exiled for a period of time if they were deemed to be a threat to the state. In modern times, ostracism is still used as a way to punish people who have committed a crime or violated social norms.