'reward' originates from Old French, specifically the word 'reguardier,' where 're-' meant 'again' and 'guarder' meant 'to watch or guard.'

'reguardier' transformed into the Middle English word 'rewarden,' and eventually became the modern English word 'reward.'

Initially, it meant 'to watch over again,' but over time it evolved into its current meaning of 'to give something in return for effort or service.'