'unrevealed' originates from the prefix 'un-' meaning 'not' and the verb 'reveal' from Latin 'revelare', where 're-' meant 'again' and 'velare' meant 'to cover'.

'revelare' transformed into the Old French word 'reveler', and eventually became the modern English word 'reveal'.

Initially, 'reveal' meant 'to uncover or disclose', and this meaning has largely remained the same in modern usage.