'unadulterated' originates from Latin, specifically the word 'adulterare,' where 'ad-' meant 'to' and 'alterare' meant 'to change.'

'adulterare' transformed into the Old French word 'adulterer,' and eventually became the modern English word 'adulterate,' with 'unadulterated' forming as its negative.

Initially, it meant 'to change or corrupt,' but over time it evolved into its current meaning of 'pure or untainted.'