'approximate' originates from Latin, specifically the verb 'approximare', where the prefix 'ad-' (in assimilated form 'ap-') meant 'toward' and 'proximus' meant 'nearest'.

'approximare' (Latin) passed into Late Latin and then entered English via scholarly/learned borrowings in the early modern period, becoming the modern English word 'approximate'.

Initially it carried the sense 'to bring near' or 'make near'; over time it evolved to the senses 'to estimate roughly' and 'to be nearly the same' in modern usage.