| mysterious(strange, remote, indefinite, unidentified) |
| remote(strange, mysterious, indefinite, unidentified) |
| secret(strange, remote, mysterious, indefinite) |
| so-and-so(strange, remote, mysterious, indefinite) |
| strange(adjective, remote, mysterious, indefinite) |
| such-and-such(strange, remote, mysterious, indefinite) |
| unapprehended(strange, remote, mysterious, indefinite) |
| unascertained(strange, remote, mysterious, indefinite) |
| uncharted(strange, remote, mysterious, indefinite) |
| undiscovered(adjective, obscure, strange, remote) |
| unexplained(strange, remote, mysterious, indefinite) |
| unexplored(strange, remote, mysterious, indefinite) |
| unfamiliar(adjective, obscure, strange, remote) |
| unidentified(adjective, strange, remote, mysterious) |
| unperceived(strange, remote, mysterious, indefinite) |
| unrecognized(strange, remote, mysterious, indefinite) |
| unrevealed(strange, remote, mysterious, indefinite) |
| untold(strange, remote, mysterious, indefinite) |