unknown
gb/ʌnnˈoʊn/ us/ʌnnˈoʊn/
A2
English
~ 2100
Senses
0 senses
adjective
A2
property
1
Not known or identified
Not known or recognized by people.
Usage pattern:
[something] is unknown
Common mistake:
Learners sometimes confuse 'unknown' with 'strange'; 'unknown' simply means not known, while 'strange' implies unusual or odd.
Synonyms
unfamiliar (Suggests something not previously experienced or recognized.)
|
unidentified (Specifically means not having been officially recognized or named.)
Antonyms
known (Means recognized, familiar, or identified.)
|
familiar (Means something is recognized from previous experience.)
Collocations
remain unknown
|identity unknown
|unknown source
|unknown reason
|unknown location
Themes
knowledge
|information
|mystery
|core_vocabulary
Examples
- The cause of the fire is still unknown.
- Her whereabouts are currently unknown to the police.
- The substance was of an unknown origin.
- The author of the letter remains unknown.
- We sailed into unknown waters.
Learner examples
- The reason is unknown.
- His name is unknown to me.
- The place is unknown.
- The answer is unknown.
- This animal is unknown in my country.
Noun
B1
entity
2
A person or thing not known
A person or thing that people do not know about.
Usage pattern:
an unknown [person/thing]
Synonyms
stranger (Usually refers to a person you have never met, but may be known to others.)
|
outsider (Refers to someone not belonging to a group, not necessarily unknown in identity.)
Antonyms
celebrity (A person widely known by the public.)
|
famous person (Someone who is well-known to many people.)
Collocations
a complete unknown
|an unknown quantity
|a relative unknown
Themes
people
|mystery
|core_vocabulary
Examples
- The actor was a complete unknown before the film.
- She was an unknown in the art world until last year.
- He faced an opponent who was an unknown to him.
Learner examples
- He is an unknown in sports.
- She was an unknown before the show.
- That singer was an unknown last year.
Noun
technical
B2
entity
3
Variable with undetermined value
In math or science, something with a value you do not know yet.
Synonyms
variable (A symbol representing a quantity that can change or be assigned different values.)
Antonyms
constant (A value that does not change and is already determined.)
Collocations
solve for the unknown
|find the unknowns
Themes
science
|mathematics
|education
Examples
- In this equation, x is the unknown.
- We need to solve for the three unknowns in the system.
- The experiment aims to identify the unknowns in the mixture.
Learner examples
- X is the unknown in this problem.
- We must find the unknown number.
- There are two unknowns in this question.
Grammar
Dictionary form
unknown
IPA
GB/ʌnnˈoʊn/
US/ʌnnˈoʊn/
Syllables & stress
un - known (2 syllables)
Stress on 2nd syllable (known)
Word forms
Adjective
- Base: unknown
Noun
- Base: unknown
- Plural: unknowns
Word family
Expressions
fear of the unknown
1/fˈɪɹ əv ðə ʌnnˈoʊn/
fixed phrase
Fear of things not understood
Feeling afraid because you do not know what will happen or do not understand something.
Examples
- Many people have a fear of the unknown when starting a new job.
- Her fear of the unknown kept her from traveling abroad.
the great unknown
1/ðə ɡɹˈeɪt ʌnnˈoʊn/
fixed phrase
Vast unexplored or mysterious thing
Something very big and mysterious that people have not explored or understood yet.
Examples
- Space has always been called the great unknown.
- The expedition set out into the great unknown.
unknown quantity
1/ʌnnˈoʊn kwˈɔntɪti/
fixed phrase
Unpredictable due to being unfamiliar
A person or thing you do not know much about, so you cannot predict what they will do.
Examples
- The new player is an unknown quantity for the team.
- The new player is an unknown quantity to the team.
- In politics, she is still an unknown quantity.
- Her abilities are still an unknown quantity in this field.