'disfavor' originates from Middle English, specifically the word 'disfavour', where 'dis-' meant 'lack of' and 'favour' meant 'approval or support'.

'disfavour' changed from the Old French word 'desfavor' and eventually became the modern English word 'disfavor'.

Initially, it meant 'lack of approval or support', and this meaning has largely remained the same in modern usage.