known

known — adjective

1. Recognized or understood by many people because it has been seen, heard about, o

1.adjectiveA2
Definition

Recognized or understood by many people because it has been seen, heard about, or experienced before.

Example

Tariro is a known expert in designing houses that use very little energy.

known + [role noun] — describing a person's recognized position

There are no known cases of this illness in Hoa's village.

no known + [noun] — negated collocation for absence of record

Common collocations
  • known fact
  • known case
  • known quantity
  • known figure
  • well known
  • widely known
  • commonly known
  • known for
  • known to
Synonyms
  • familiar

    emphasises personal recognition rather than public awareness; 'a familiar face' feels more personal than 'a known face'

  • recognized

    slightly more formal, often implies official or expert acknowledgement

  • acknowledged

    stronger — implies acceptance of something as true or valid, not just awareness

Antonyms
  • unknown

    direct opposite; not recognized or understood by people

  • unfamiliar

    focuses on lack of personal experience rather than public knowledge

Grammar Patterns

known for + [characteristic]

known to + [group of people]

well-known + [noun]

Common Mistakes

This is a known fact for scientists.
This fact is known to scientists.
Use 'known to' (not 'known for') when specifying the group of people who recognize something.
The actor is known as playing comedic roles.
The actor is known for playing comedic roles.
Use 'known for' (not 'known as') when giving a characteristic or activity.

2. Describes a person or thing that has a particular name or title which people use

2.adjectiveB1
Definition

Describes a person or thing that has a particular name or title which people use to refer to them.

Example

Dr. Ishaan Mehta, known as 'the heart doctor' by his patients, works at a hospital in Mumbai.

known as + [nickname/title]

This long-legged bird, known as a secretary bird, hunts snakes on the African plains.

Common collocations
  • known as
  • also known as
  • better known as
  • commonly known as
  • known locally as
Synonyms
  • called

    more direct and informal; 'a plant called aloe vera' is everyday speech

  • named

    used for specific given names; slightly more formal than 'called'

  • referred to as

    more formal; common in academic or official writing

Grammar Patterns

known as + [name/title]

also known as + [alternative name]

better known as + [more familiar name]

Usage Note

Distinguish from sense 1: 'known for' (sense 1) gives a reason or characteristic, while 'known as' (sense 2) gives a name, title, or label. For example, a doctor is known as 'Dr. Chen' (her name) but known for her careful surgery (her quality). These two patterns are not interchangeable.

Common Mistakes

She is known for the school nurse.
She is known as the school nurse.
Use 'known as' for a role or title, not 'known for.'
This plant is known as its healing properties.
This plant is known for its healing properties.
Use 'known for' for a characteristic; use 'known as' only for a name.

3. No longer kept secret or private; having been told to other people so that it is

3.adjectiveB2
Definition

No longer kept secret or private; having been told to other people so that it is now public information.

Example

The full details of the agreement became known after the press conference.

became known — passive verb pattern for disclosure

The full story of the missing sculpture became known after Indra found the original receipt.

became known — passive verb pattern for disclosure

Common collocations
  • become known
  • make known
  • publicly known
  • well-known
  • known fact
Synonyms
  • disclosed

    more formal; often used in legal or official contexts

  • revealed

    stronger — implies something was hidden or secret before

  • publicized

    emphasises that information was actively spread to many people

Antonyms
  • secret

    not disclosed or revealed to others

  • hidden

    kept out of sight or deliberately concealed

Grammar Patterns

become known

make + [noun] + known

Usage Note

Frequently used with the verbs 'become' or 'make' to show the process of information being disclosed.

Common Mistakes

He known his decision yesterday.
He made his decision known yesterday.
'Known' as an adjective cannot stand alone as the main verb; it needs 'make', 'become', or another linking verb.
The secret was known by the press last week.
The secret became known to the press last week.
Use 'became known to' (not 'was known by') to show the moment of revelation.

Word family

Synonym discussion

Sense: adjective/1

All four words describe something that is not new or not unknown, but they differ in scope and formality. 'Known' is the broadest and most neutral term: a known fact is simply one that people are aware of. 'Familiar' adds a personal dimension — a familiar face is one you have personally seen before, even if others would not recognize it. 'Recognized' suggests official or expert acknowledgement, as in a recognized qualification or a recognized authority. 'Well-known' implies wide public awareness: a well-known landmark is known to many people across regions. For example, the Earth is round is a known fact among educated people, but it is so universally accepted that it is also well-known. Maria's face is familiar to her colleagues but she is not well-known outside her office. A recognized expert in a field has official standing that goes beyond being merely known.

known ↗familiar ↗recognizedwell-known ↗

Common collocations

Nouns

Adverbs

Phrases

  • known as
  • known for
  • known to
  • also known as
  • better known as
  • make known
  • become known

Prepositions

Etymology

Proto-Indo-EuropeanProto-GermanicOld EnglishMiddle EnglishModern English

The word 'known' comes from Old English 'cnāwen', the past participle of 'cnāwan' meaning 'to know'. This root traces back to Proto-Germanic '*knēaną' and ultimately to the Proto-Indo-European root '*ǵneh₃-', which means 'to know'. Many modern English words share this ancient root, including 'recognize' (via Latin 'cognoscere'), 'notion' (via Latin 'notus'), and 'narrate' (via Latin 'gnarus'). The same Indo-European source also gives us the Greek 'gignōskein' (to know) — seen in English words like 'diagnosis' and 'prognosis.'