known

Etymology

From Middle English knowen, from Old English cnāwen (past participle). Morphologically know + -n.

adj

1. Identified as a specific type; famous, renowned.
   He was a known pickpocket.
2. Accepted, familiar, researched.
   As we age, the major arteries of our bodies frequently become thickened with plaque, a fatty material with an oatmeal-like consistency that builds up along the inner lining of blood vessels. The reason plaque forms isn’t entirely known, but it seems to be related to high levels of cholesterol inducing an inflammatory response, which can also attract and trap more cellular debris over time. 2013 July-August, Stephen P. Lownie, David M. Pelz, “Stents to Prevent Stroke”, in American Scientist

noun

1. Any fact or situation which is known or familiar.
   You have to tell the knowns from the unknowns.
   The biological dereplication tool may identify major knowns in a mixture, but it may miss novel minor components. 2012, Thomas Dougherty, Antibiotic Discovery and Development, volume 1, page 39
2. (algebra) A constant or variable the value of which is already determined.

verb

1. past participle of know