Definition of "known"

Being not knowne, some great persons in the pew I pretended to, and went in, did question my coming in.

1664 April 4 (date written; Gregorian calendar), Samuel Pepys, Mynors Bright, transcriber, “March 25th, 1664 (Lady day)”, in Henry B[enjamin] Wheatley, editor, The Diary of Samuel Pepys […], volume IV, London: George Bell & Sons […]; Cambridge: Deighton Bell & Co., published 1894, page 85

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

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