'idiosyncratic' originates from Greek, specifically the word 'idiosynkrasia,' where 'idios' meant 'own' and 'synkrasis' meant 'mixture.'

'idiosynkrasia' transformed into the Late Latin word 'idiosyncrasia,' and eventually became the modern English word 'idiosyncratic.'

Initially, it meant 'a peculiar temperament or constitution,' but over time it evolved into its current meaning of 'peculiar or individual.'