UNKNOWN

Definition

1. noun an unknown and unexplored region. — synonyms: unknown_region, terra_incognita
2. noun anyone who does not belong in the environment in which they are found. — synonyms: stranger, alien
3. noun a variable whose values are solutions of an equation. — synonyms: unknown_quantity
4. adjective not known.
5. adjective being or having an unknown or unnamed source. — synonyms: nameless, unidentified, unnamed
6. adjective not known to exist.
7. adjective not famous or acclaimed. — synonyms: obscure, unsung
8. adjective not known before. — synonyms: strange