adjective / noun

unknown

Not known or identified, or something not yet known.

The cause of the strange noise is still unknown.

Etymology

The negative prefix denies knowledge or identification. The adjective can also stand as a noun for the thing not yet known.

More examples

  • An unknown caller leaves a message on my phone.
  • Too many unknowns remain for us to make a decision.
  • She faces the unknown with more curiosity than fear.

Forms

unknown · unknowns

Similar words

unidentified
Specifically means that someone's or something's identity has not been established.
unfamiliar
Emphasizes a person's lack of experience with or recognition of something.
mysterious
Suggests something puzzling or secret, not simply unknown.