'unsoiled' originates from the Old English prefix 'un-' combined with the verb 'soil', which ultimately originates from Old French, specifically the word 'soillier', where 'soillier' meant 'to make dirty'.

'unsoiled' changed from the Middle English formation of 'un-' + the past participle 'soiled' (from French 'soillier'), and eventually became the modern English adjective 'unsoiled'.

Initially, it meant 'not made dirty', and over time it has retained its current meaning of 'not dirty or unstained'.