'unwrinkled' originates from the prefix 'un-' meaning 'not' and the word 'wrinkled', which comes from Middle English 'wrinkel', meaning 'a small fold or crease'.

'wrinkel' transformed into the modern English word 'wrinkle', and with the addition of the prefix 'un-', it became 'unwrinkled'.

Initially, 'wrinkle' meant 'a small fold or crease', and 'unwrinkled' has consistently meant 'without wrinkles'.