'unspecified' originates from the prefix 'un-' meaning 'not' and the word 'specified' from Latin 'specificare', where 'speci-' meant 'kind' or 'type' and '-ficare' meant 'to make'.

'specificare' transformed into the Old French word 'specifer', and eventually became the modern English word 'specify', with 'un-' added to form 'unspecified'.

Initially, it meant 'not made specific', and this meaning has largely remained the same in modern usage.