'banish' originates from Old French, specifically the word 'banir', where 'ban' meant 'proclamation' and '-ir' was a verb-forming suffix.

'banir' transformed into the Middle English word 'banishen', and eventually became the modern English word 'banish'.

Initially, it meant 'to proclaim or announce', but over time it evolved into its current meaning of 'to expel or send away'.