'courteous' originates from Old French, specifically the word 'curteis', where 'curt' meant 'court' and '-eis' was a suffix indicating 'pertaining to'.

'curteis' transformed into the Middle English word 'curteys', and eventually became the modern English word 'courteous'.

Initially, it meant 'having manners befitting a court', but over time it evolved into its current meaning of 'polite and respectful'.