Meaning of UNKNOWN in English

UNKNOWN

I. -ˈnōn adjective

Date: 14th century

: not known or not well-known ; also : having an unknown value

an unknown quantity

II. noun

Date: 1597

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

Merriam-Webster's Collegiate English vocabulary.      Энциклопедический словарь английского языка Merriam Webster.