'idiomatic' originates from Greek, specifically the word 'idiōmatikos,' where 'idiōma' meant 'peculiarity, special feature.'

'idiōmatikos' transformed into the Late Latin word 'idiomaticus,' and eventually became the modern English word 'idiomatic.'

Initially, it meant 'peculiar to a language,' but over time it evolved into its current meaning of 'relating to or conforming to the natural manner of expression in a language.'