known
nohn
Known (adjective) means Recognized or identified as a particular type of person or thing; well-established in reputation. Example: “He is a known troublemaker at the office.”
adjective
1
Recognized or identified as a particular type of person or thing; well-established in reputation.
"He is a known troublemaker at the office."
"She is known for her honesty and hard work."
"He is a known fan of the local football team."
2
Familiar, understood, or already established as fact.
"Scientists studied the known effects of the drug before testing a new dose."
"There are no known cures for the common cold."
"Nut allergies are a known risk, so we label every cake clearly."
noun
1
Something that is already established or understood, as opposed to the unknown.
"The detective preferred to work from the knowns before guessing at the rest."
"In science, you build new theories on top of the knowns."
"Good planners separate the knowns from the unknowns before starting a project."
2
In mathematics, a quantity whose value has already been determined, as opposed to a variable being solved for.
"The equation had two knowns and one unknown to solve for."
"She plugged the knowns into the formula to find x."
"In the problem, the speed and the time are the knowns; the distance is not."
How to use known
Learner’s notesIn plain EnglishAlready recognized, identified, or established as fact — the opposite of unknown.
Common mistake
As a noun ("the knowns and unknowns"), it is mainly used in science, math, and formal writing — in everyday speech people usually just say "what we know."
Common pairings
a known fact
known for
known as
well known
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Word forms
- Plural
- knowns
- Comparative
- better known
- Superlative
- best known
Fill the gap
Can you complete this real example?
He is a _____ troublemaker at the office.
Etymology
The past participle of "know," from Old English cnāwan, ultimately from a very old root meaning "to recognize" that also gave us "notice" and "note" in other languages.
Synonyms
View more →Antonyms
Related words
Rhymes for known
See all rhymes for known →Frequently asked questions
What does “known” mean?
The word “known” means recognized or identified as a particular type of person or thing; well-established in reputation. In plain terms, already recognized, identified, or established as fact — the opposite of unknown.
How do you pronounce “known”?
“Known” is pronounced nohn (/noʊn/ in IPA).
How do you use “known” in a sentence?
Here is “known” used in a sentence: “He is a known troublemaker at the office.”
What part of speech is “known”?
Depending on how it is used, “known” can be an adjective and a noun.
Where does the word “known” come from?
The word “known” comes from Old English. The past participle of "know," from Old English cnāwan, ultimately from a very old root meaning "to recognize" that also gave us "notice" and "note" in other languages.
Is “known” a common word?
“Known” is a very common word in modern English, usually learned at around the B2 level.
How many meanings does “known” have?
“Known” has 4 distinct senses listed in this dictionary. The most common is: recognized or identified as a particular type of person or thing; well-established in reputation.
What is the difference between known and famous?
"Known" simply means recognised or identified — people are aware of the person or thing, sometimes only within a small circle. "Famous" means known very widely and usually admired. A shop can be known locally without being famous. Fame is large-scale, positive recognition; being known is broader and can be quite modest.
What is the difference between known and notorious?
Both mean recognised, but "notorious" is negative — known specifically for something bad, such as a notorious criminal. "Known" on its own is neutral. Someone can be known as a fine cook, which is positive, or known as a troublemaker; "notorious" always carries the sense of a bad reputation.
What is the opposite of known?
The main opposites are "unknown" and "unrecognised" — not identified, or lacking any established reputation. Depending on the sense, "anonymous," "obscure," or "unfamiliar" also work. A known figure is recognised; an unknown one is not, whether because they are new, hidden, or simply unnoticed by others.
Can 'known' describe facts as well as people?
Yes. Beyond reputation, "known" describes information established as true, as in "a known fact" or "known risks." Here it means confirmed and generally accepted rather than merely suspected. Whether applied to a person or a fact, "known" signals that something is recognised and established rather than uncertain or hidden.
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