a.
1.
Unascertained.
2.
Unexplored, uninvestigated.
3.
Mysterious, mystic, hidden, dark, enigmatical.
4.
Without the knowledge of.
5.
Obscure, undistinguished, nameless, unnoted, unhonored, renownless, inglorious.
a.
1.
Unascertained.
2.
Unexplored, uninvestigated.
3.
Mysterious, mystic, hidden, dark, enigmatical.
4.
Without the knowledge of.
5.
Obscure, undistinguished, nameless, unnoted, unhonored, renownless, inglorious.
Soule. Dictionary of English synonyms. Словарь английских синонимов. 2012