'reimbursement' originates from the Latin word 'reimbursare', where 're-' meant 'again' and 'imbursare' meant 'to put in a purse'.

'reimbursare' transformed into the Old French word 'reembourser', and eventually became the modern English word 'reimburse' through Middle English.

Initially, it meant 'to put money back into a purse', but over time it evolved into its current meaning of 'compensating for expenses'.