unknown:1

adjective
un*known \ ˌən-ˈnōn \
14th century
  • not known or not well-known; also : having an unknown value

unknown:2

noun
unknown \
1597{ds||1||}
  • one that is not known or not well-known; especially : a person who is little known (as to the public)
  • something that requires discovery, identification, or clarification: such as
  • a symbol (such as x, y, or z) in a mathematical equation representing an unknown quantity

Unknown Soldier

noun
Unknown Soldier \
1923
  • an unidentified soldier whose body is selected to receive national honors as a representative of all of the same nation who died in a war and especially in one of the world wars

unknown quantity

noun
unknown quantity \
  • someone or something whose abilities or characteristics are not yet known

unknown to

idiom
unknown to \
  • without being known about by (someone)

big unknown

noun
big unknown \
  • the important thing that everyone would like to know

of unknown origin

idiom
of unknown origin \
  • —used to say that the source or cause of something is not known

the unknown

noun
the unknown \
  • a place, situation, or thing that is not known about or understood : a situation that one is unfamiliar with
Powered by Merriam-Webster