'endorse' originates from Medieval Latin, specifically the word 'indorsare,' where 'in-' meant 'on' and 'dorsum' meant 'back.'

'indorsare' transformed into the Old French word 'endosser,' and eventually became the modern English word 'endorse' through Middle English.

Initially, it meant 'to write on the back of a document,' but over time it evolved into its current meaning of 'to approve or support.'