'demonstrate' originates from Latin, specifically the word 'dēmonstrāre,' where 'dē-' meant 'completely' and 'monstrāre' meant 'to show.'

'dēmonstrāre' transformed into the Old French word 'demontrer,' and eventually became the modern English word 'demonstrate' through Middle English.

Initially, it meant 'to show or point out,' but over time it evolved into its current meaning of 'to prove or make clear.'