'inauthentic' originates from the prefix 'in-' meaning 'not' and the word 'authentic', which comes from the Greek word 'authentikos', meaning 'original' or 'genuine'.

'inauthentic' evolved from the combination of the prefix 'in-' with 'authentic', which was derived from the Greek 'authentikos'.

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