'heretic' originates from Greek, specifically the word 'hairetikos', via Late Latin 'haereticus', where Greek 'hairein' meant 'to choose'.

'heretic' changed from Greek 'hairetikos' to Late Latin 'haereticus', passed into Old French as 'heretique', and eventually became the modern English word 'heretic' through Middle English.

Initially it meant 'one who chooses' (a chooser of beliefs), but over time it evolved into its current meaning of 'a person holding opinions contrary to accepted doctrine or orthodoxy'.