| nameless(adjective, knowledge, strange, unknown, indefinite) |
| unknown(adjective, obscure, mysterious, indefinite, undisclosed) |
| unidentified(adjective, strange, secret, unknown, indefinite) |
| anonymous(adjective, knowledge, strange, choice, unknown) |
| incognito(adjective, strange, unknown, indefinite, undisclosed) |
| innominate(adjective, unknown, undisclosed, nameless, anonymous) |
| unspecified(adjective, strange, unknown, indefinite, undisclosed) |
| obscure(adjective, strange, unknown, indefinite, unidentified) |
| unsung(adjective, strange, unknown, indefinite, unidentified) |
| unsigned(adjective, knowledge, unknown, undisclosed, nameless) |
| certain |
| strange(adjective, indefinite, unidentified) |
| unacknowledged |
| unheard-of(adjective, strange, unknown, indefinite, unidentified) |
| X(strange, unknown, indefinite, undisclosed, unidentified) |
| faceless |
| mysterious(adjective, strange, secret, indefinite, unidentified) |
| undefined |
| undistinguished(adjective, strange, unknown, indefinite, unidentified) |
| unfamiliar(adjective, strange, secret, indefinite, unidentified) |