'disingenuous' originates from Latin, specifically the word 'ingenuus,' where 'in-' meant 'not' and 'genuus' meant 'natural or genuine.'

'ingenuus' transformed into the Late Latin word 'disingenuus,' and eventually became the modern English word 'disingenuous.'

Initially, it meant 'not noble or freeborn,' but over time it evolved into its current meaning of 'insincere or deceitful.'