'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,' and this meaning has largely remained the same in modern usage.