unknown

²unknown

noun

Definition of UNKNOWN

1

: one that is not known or not well-known; especially : a person who is little known (as to the public)

2

: something that requires discovery, identification, or clarification: as a : a symbol (as x, y, or z) in a mathematical equation representing an unknown quantity b : a specimen (as of bacteria or mixed chemicals) required to be identified as an exercise in appropriate laboratory techniques

Examples of UNKNOWN

1. explorers venturing off into the unknown
2. A fear of the unknown kept her from changing jobs.
3. The director cast an unknown in the lead role.
4. We're facing too many unknowns.

First Known Use of UNKNOWN

1597