I. ˈnōn sometimes -ōən adjective
Etymology: Middle English knowen, knawen, from past participle of knowen, knawen to know — more at know
: that is apprehended or perceived by the mind or senses : that has become a part of knowledge
a known truth that no one denies
: familiar through knowledge or experience
beyond the limits of the known world — A.C.Whitehead
especially : generally recognized
a known authority in this matter
II. noun
( -s )
1. : something known : something familiar or recognized ; specifically : a substance of known composition — used especially in chemical analysis
chemical determinations performed on knowns — A.A.Benedetti-Pichler
2. : a letter (as in a 2 + 2 ab ) or some other symbol (as π) used in a mathematical equation to represent a known number or quantity