| undetected(adjective, knowledge, obscure, dark, unknown) |
| undisclosed(adjective, obscure, dark, secret, unknown) |
| undiscovered(adjective, knowledge, obscure, untraveled, unfound) |
| invisible(adjective, obscure, dark, unknown, hidden) |
| unknown(adjective, obscure, dark, secret, hidden) |
| latent(adjective, obscure, dark, unknown, hidden) |
| unrevealed(adjective, obscure, dark, secret, unknown) |
| clandestine(adjective, latent) |
| concealed(adjective, latent) |
| covert(adjective, latent) |
| hidden(adjective, secret, unseen, latent) |
| mysterious(adjective, obscure, dark, secret, unknown) |
| obscure(adjective, dark, secret, unknown, hidden) |
| secure |
| unapparent(adjective, latent) |
| unfamiliar(adjective, unfound) |
| uncharted(adjective, unfound) |
| unexplored(adjective, unfound) |
| unfound(adjective, knowledge, obscure, undiscovered, untraveled) |
| unheard-of(adjective, unfound) |