| secret(adjective, hidden, clandestine, underground, undisclosed) |
| hidden(adjective, clandestine, underground, undisclosed) |
| private(adjective, obscure, unknown, clandestine, underground) |
| unexpressed(adjective, latency implication) |
| untold |
| undisclosed(adjective, obscure, unknown, clandestine, underground) |
| unsaid |
| unsung |
| unwritten(adjective, latency implication) |
| clandestine(adjective, underground, undisclosed) |
| classified(adjective, obscure, unknown, clandestine, underground) |
| covert(adjective, clandestine, underground, undisclosed) |
| inedited |
| unexposed |
| unknown(adjective, obscure, clandestine, underground, undisclosed) |
| unrevealed(adjective, obscure, unknown, clandestine, underground) |
| backdoor(obscure, deep, unknown, clandestine, underground) |
| confidential(adjective, clandestine, underground, undisclosed) |
| cryptic(adjective, obscure, unknown, clandestine, underground) |
| deep(adjective, obscure, unknown, clandestine, underground) |