'two-fold' originates from Old English, specifically the word 'twifald', where 'twi-' meant 'two' and '-fald' meant 'fold, times'.

'twifald' changed into Middle English forms such as 'twifold' or 'twofold' and eventually became the modern English 'two-fold' (also written 'twofold').

Initially, it meant 'two times' or 'double,' and over time this core sense survived into modern usage as both 'consisting of two parts' and 'twice as much'.