adj. & n.
--adj. (often foll. by to) not known, unfamiliar (his purpose was unknown to me).
--n.
1. an unknown thing or person.
2 an unknown quantity (equation in two unknowns).
Phrases and idioms:
unknown country see COUNTRY. unknown quantity a person or thing whose nature, significance, etc., cannot be determined. Unknown Soldier an unidentified representative member of a country's armed forces killed in war, given burial with special honours in a national memorial. unknown to without the knowledge of (did it unknown to me). Unknown Warrior Unknown Soldier.
Derivatives:
unknownness n.