untrue
gb/ʌntɹˈu/ us/ʌntɹˈu/
B1
English
~ 10000
Senses
0 senses
adjective
B1
property
1
not true; false
Not true; not correct when you compare it with real facts.
Usage pattern:
[statement/claim/belief] is untrue
Common mistake:
Learners often use *wrong* instead of *untrue* for statements or facts. *Wrong* is possible but usually sounds more casual or emotional (e.g., "That’s wrong"); *untrue* is more factual or careful, especially in news or formal speech. Another mistake is using *untruth* when they simply mean *untrue*; *untruth* is a noun meaning a lie, while *untrue* is an adjective describing a statement.
Synonyms
false (Very close in meaning; slightly more common in everyday speech for facts and statements.)
|
incorrect (Often used for answers, data, or details rather than rumors or accusations.)
Antonyms
true (Direct opposite; describes statements or facts that match reality.)
|
accurate (Opposite when talking about detailed or precise information that matches the facts.)
Collocations
completely untrue
|entirely untrue
|claims are untrue
|prove [something] untrue
|untrue statement
|untrue rumor
Themes
communication
|media
|knowledge
|education
|core_vocabulary
Examples
- The company insists that the reports of a data breach are untrue.
- He later admitted that his earlier comments about the mayor were untrue.
- Several experts have said that the claims in the video are simply untrue.
- The article was pulled after the newspaper realized parts of the story were untrue.
Learner examples
- His story was untrue, and he knew it.
- The rumor about her losing her job is untrue.
- She said the joke was funny but that would be untrue.
- The news report was untrue and caused a lot of fear.
adjective
B2
property
2
not faithful; unloyal
Not faithful or loyal to a person or to what you have promised.
Usage pattern:
[someone] is untrue to [someone/something]
Common mistake:
Learners sometimes confuse *untrue* with *fake* or *false* when talking about people. *Untrue* is not used to mean a person is not real; it describes being unfaithful or disloyal (e.g., "untrue to his wife"). For objects like a *fake bag*, you should not say *an untrue bag*.
Synonyms
unfaithful (Very close in meaning; more common for romantic or sexual betrayal.)
|
disloyal (Similar but a bit broader; often used for friends, countries, or causes, not just romantic partners.)
Antonyms
faithful (Direct opposite; stresses staying with one partner or keeping a promise.)
|
loyal (Opposite in the sense of continuing to support a person, group, or belief.)
Collocations
be untrue to [someone]
|untrue to his wife
|untrue to her partner
|untrue to his principles
|untrue to their values
Themes
relationships
|ethics
|emotions
|core_vocabulary
Examples
- He felt terrible for being untrue to his wife while he was away on business.
- By hiding the results, the scientist was untrue to the basic principles of honesty in research.
- The film is untrue to the spirit of the original novel, changing the main character completely.
- She refused to be untrue to her values just to keep her job.
Learner examples
- He was untrue to his girlfriend, and their relationship ended.
- She did not want to be untrue to her best friend.
- They said the movie was untrue to the book.
- He felt he was untrue to himself when he lied.
adjective
technical
C1
property
3
not straight; mechanically off
Not straight or in the right line, especially when a wheel or similar part moves in a side-to-side way.
Usage pattern:
[mechanical part] is untrue
Common mistake:
Learners rarely use this technical sense; a possible confusion is thinking *untrue* here still means *false*. In this context, it is about shape and movement, not about truth or lies.
Synonyms
warped (Similar for objects that are bent or twisted, but less specific to rotating parts.)
|
out of true (Technical phrase meaning not exactly straight or aligned; often used for wheels or frames.)
Antonyms
true (In technical use, means exactly straight or correctly aligned, especially when something rotates smoothly.)
|
aligned (Opposite in the sense of parts being correctly lined up.)
Collocations
untrue wheel
|untrue rim
|slightly untrue
|wheel has gone untrue
Themes
technology
|sports
|transportation
|work
Examples
- After the crash, the front wheel of the bike was badly untrue and rubbed against the brake pads.
- The mechanic said the rim was untrue and needed to be straightened before the race.
- If the disc is untrue, the whole machine will vibrate at high speed.
Learner examples
- My bicycle wheel is untrue and it shakes.
- The rim became untrue after I hit a rock.
- He fixed the untrue wheel in his small workshop.
Grammar
Dictionary form
untrue
IPA
GB/ʌntɹˈu/
US/ʌntɹˈu/
Syllables & stress
un - true (2 syllables)
Stress on 2nd syllable (true)
Word forms
Adjective
- Base: untrue
Word family
Related words
truthful
adjective B1
truthfully
adverb
Negative and opposite forms
untruth
noun
untruthful
adjective
Advanced or less common
truthfulness
noun B2
Expressions
be untrue to [someone]
1/bˈi ʌntɹˈu tə sˈʌmwˌʌn/
fixed phrase
be romantically unfaithful
To cheat on your boyfriend, girlfriend, husband, or wife by having a romantic or sexual relationship with another person.
Examples
- He had been untrue to his wife for years before she found out.
- She promised never to be untrue to him again after the affair.
be untrue to [something]
1/bˈi ʌntɹˈu tə sˈʌmθɪŋ/
fixed phrase
not follow values or style
To behave in a way that does not match your usual character, beliefs, style, or promises.
Examples
- The new policy is untrue to the company’s original mission.
- Many fans felt the sequel was untrue to the spirit of the first movie.
prove [something] untrue
1/pɹˈuv sˈʌmθɪŋ ʌntɹˈu/
fixed phrase
show that something is false
To show by using facts or evidence that a statement, rumor, or idea is not true.
Examples
- The investigation proved the allegations untrue.
- New research has proved many of these fears untrue.
untrue to life
1/ʌntɹˈu tə lˈaɪf/
fixed phrase
not realistic; not lifelike
Not realistic; not showing people, events, or details in a way that is close to real life.
Examples
- Critics said the courtroom scenes were untrue to life.
- The dialogue sounds untrue to life and very unnatural.