'threadlike' originates from the combination of 'thread' and the suffix '-like', where 'thread' meant 'a thin strand of fiber' and '-like' meant 'resembling or similar to'.

'thread' changed from Old English word 'þræd' and eventually became the modern English word 'thread'.

Initially, it meant 'resembling a thin strand of fiber', and this meaning has largely remained the same in modern usage.