'accustomize' originates from the English word 'accustom,' which is derived from the Old French word 'acostumer,' where 'a-' meant 'to' and 'costume' meant 'habit or custom.'

'acostumer' transformed into the Middle English word 'accustumen,' and eventually became the modern English word 'accustom.'

Initially, it meant 'to make familiar with a custom or habit,' and this meaning has largely remained the same in modern usage.