'affirmer' originates from Old French, specifically the word 'affirmer', where 'ad-' meant 'to' and 'firmare' meant 'make firm'.

'affirmer' changed from the Old French word 'affirmer' and eventually became the modern English word 'affirmer'.

Initially, it meant 'to make firm or confirm', but over time it evolved into its current meaning of 'one who affirms'.