'untainted' originates from Middle English, specifically the word 'taint,' where 'un-' meant 'not' and 'taint' meant 'to stain or corrupt.'

'taint' transformed into the modern English word 'untainted' by adding the prefix 'un-' to indicate the absence of taint.

Initially, it meant 'not stained or corrupted,' and this meaning has largely remained the same in modern usage.