Meanings
nounknown known (plural known knowns)
plural known knowns
- Certainties of known magnitude, consequence, structure, and probability characteristics; something that we know that we know.
Origin
Popularized by Donald Rumsfeld in 2002, though used much earlier.
Full word history & related roots →Cite this entry
APA
known known. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/known%20known
MLA
“known known.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/known%20known. Accessed November 4, 2026.
Chicago
WatkinsX Dictionary, s.v. “known known,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/known%20known.
Source: known known on Wiktionary, CC BY-SA 4.0.