'forestall' originates from Old English, specifically the word 'foresteall,' where 'fore-' meant 'before' and 'steall' meant 'position or place.'

'foresteall' changed from Old English word 'foresteall' and eventually became the modern English word 'forestall'.

Initially, it meant 'to intercept or waylay,' but over time it evolved into its current meaning of 'to prevent or obstruct by taking action ahead of time.'