'unkind' originates from Old English, specifically the word 'uncynde,' where 'un-' meant 'not' and 'cynde' meant 'natural' or 'kind.'

'uncynde' transformed into the Middle English word 'unkinde,' and eventually became the modern English word 'unkind.'

Initially, it meant 'not natural or not kind,' but over time it evolved into its current meaning of 'lacking kindness.'