Secret

1. To keep secret.
2. Something studiously concealed; a thing kept from general knowledge; what is not revealed, or not to be revealed.
3. Hidden; concealed; as, secret treasure; secret plans; a secret vow.
4. Withdraw from general intercourse or notice; in retirement or secrecy; secluded.
5. Faithful to a secret; not inclined to divulge or betray confidence; secretive.
6. Separate; distinct.
7. The parts which modesty and propriety require to be concealed; the genital organs.
8. A thing not discovered; what is unknown or unexplained; a mystery.