| undiscovered(strange, remote, mysterious, private) |
| undistinguished(adjective, obscure, strange, remote) |
| unexplained(strange, remote, mysterious, indefinite) |
| unheard-of(adjective, unusual, strange, remote) |
| unidentified(strange, remote, mysterious, indefinite) |
| unnoted(strange, remote, indefinite, unidentified) |
| unperceived(strange, remote, mysterious, indefinite) |
| unrecognized(strange, remote, mysterious, indefinite) |
| unrenowned(strange, remote, mysterious, indefinite) |
| unrevealed(strange, remote, mysterious, indefinite) |
| unsung(strange, remote, indefinite, unidentified) |
| untold(strange, remote, mysterious, indefinite) |
| untried(unusual, strange, mysterious, unknown) |
| original(adjective, obscure, strange, different) |
| out-of-the-way(unknown, untried) |
| recondite(unknown, untried) |
| remarkable(unusual, strange, unknown, untried) |
| uncommon(adjective, obscure, unusual, strange) |
| unexpected(unusual, strange, unknown, untried) |
| uninvestigated(unknown, untried) |