'forethought' originates from Old English, specifically the word 'foreþencan,' where 'fore-' meant 'before' and 'þencan' meant 'to think.'

'foreþencan' transformed into the Middle English word 'forethought,' and eventually became the modern English word 'forethought.'

Initially, it meant 'to think beforehand,' but over time it evolved into its current meaning of 'careful consideration of future needs or events.'