'twofold' originates from Old English, specifically the word 'twēofald', where 'twēo-' meant 'two' and '-fald' meant 'fold'.

'twēofald' transformed into the Middle English word 'twofald', and eventually became the modern English word 'twofold'.

Initially, it meant 'having two parts', and this meaning has largely remained the same in modern usage.