not known; not within the range of one's knowledge, experience, or understanding; strange; unfamiliar.
not discovered, explored, identified, or ascertained: the unknown parts of Antarctica.
not widely known; not famous; obscure: an unknown writer.
noun
a thing, influence, area, factor, or person that is unknown: the many unknowns in modern medicine; The director cast an unknown in the leading role.
Mathematics. a symbol representing an unknown quantity: in algebra, analysis, etc., frequently represented by a letter from the last part of the alphabet, as x, y, or z.
Origin of unknown
First recorded in 1250–1300,unknown is from the Middle English word unknow(e)n. See un-1, known
not established, identified, or discoveredan unknown island
not famous; undistinguishedsome unknown artist
unknown quantitya person or thing whose action, effect, etc, is unknown or unpredictable
noun
an unknown person, quantity, or thing
mathsa variable, or the quantity it represents, the value of which is to be discovered by solving an equation; a variable in a conditional equation3y = 4x + 5 is an equation in two unknowns
c.1300, "strange, unfamiliar" (of persons, places), from un- (1) "not" + past participle of know. Cf. Old English ungecnawen. In reference to facts, attested from early 14c. The noun meaning "unknown person" is recorded from 1590s.
