'acost' originates from Old French, specifically the word 'acoster,' where 'a-' meant 'to' and 'coster' meant 'side.'

'acoster' transformed into the Middle English word 'acosten,' and eventually became the modern English word 'acost.'

Initially, it meant 'to come alongside,' but over time it evolved into its current meaning of 'to approach and speak to someone.'