betray

betray — verb

1. to turn against a person, group, or country that trusted you, especially by help

1.verbtransitiveB2
Definition

to turn against a person, group, or country that trusted you, especially by helping the other side or leaving them without support.

Example

One officer betrayed the army by sending maps to the enemy.

betray + group by + -ing

Mina felt betrayed when her cousin shared the private messages.

passive: feel betrayed

Common collocations
  • betray a friend
  • betray your country
  • betray the team
  • feel betrayed
Synonyms
  • double-cross

    informal and often suggests a deliberate trick against someone

  • sell out

    informal and stresses acting for money or advantage

  • desert

    focuses on leaving someone without help, not always helping the other side

  • turn against

    a broader phrase for changing sides or loyalties

Antonyms
  • support

    stresses standing by a person or group instead of turning against them

  • remain loyal to

    emphasizes keeping faith with the person or side you belong to

Grammar Patterns

betray + person/group/country

betray + object + by + -ing

feel betrayed

Usage Note

Object is usually a person, group, or country that placed trust in the subject. Distinguish from sense 2, where the object is something abstract such as a promise, value, or belief.

Common Mistakes

He betrayed to his team during the match.
He betrayed his team during the match.
'betray' takes a direct object, not 'betray to'.
Jamal betrayed with the enemy for money.
Jamal betrayed her country by working with the enemy for money.
name the person or group harmed as the object; the action can follow with 'by'.

2. to act against a promise, someone else's trust, or your own beliefs instead of s

2.verbtransitiveB2
Definition

to act against a promise, someone else's trust, or your own beliefs instead of staying true to them.

Example

By taking the bribe, the judge betrayed the trust of the public.

betray the trust of + group

Nora refused the deal because it betrayed her deepest beliefs.

betray + belief

Common collocations
  • betray a promise
  • betray trust
  • betray your values
  • betray your beliefs
Synonyms
  • break

    the broad everyday verb, especially with promise or trust

  • violate

    more formal and common with principles, rules, or agreements

  • go back on

    used especially for a promise, word, or agreement

  • abandon

    fits beliefs or principles when someone leaves them behind

Antonyms
  • keep

    the normal opposite with promise or trust

  • honour

    more formal and common with promises, duties, or agreements

  • uphold

    used especially for values, standards, or principles

Grammar Patterns

betray the trust of + noun

betray + promise/value/belief

betray + object + by + -ing

Usage Note

Object is typically an abstract thing that should be kept, such as trust, a promise, a value, or a belief. Distinguish from sense 1, which is used when the object is a person, group, or country.

Common Mistakes

She betrayed the school rule by using her phone.
She broke the school rule by using her phone.
this sense is used for promises, trust, values, or beliefs, not ordinary rules.
He betrayed that he would help us.
He broke his promise to help us.
this sense takes an object like 'promise' or 'trust', not a that-clause.

3. to let a secret, private fact, or hidden plan become known, either accidentally

3.verbtransitiveB2
Definition

to let a secret, private fact, or hidden plan become known, either accidentally or by breaking confidence.

Example

A nervous glance betrayed the surprise party before Mia opened the door.

betray + hidden plan

Tom betrayed the hiding place when he pointed at the shed.

Common collocations
  • betray a secret
  • betray the hiding place
  • betray the launch date
  • betray confidence
Synonyms
  • reveal

    the general neutral verb for making something known

  • disclose

    more formal and common in official or legal contexts

  • give away

    informal and often suggests showing something by mistake

  • let slip

    used especially when someone says something accidentally

Antonyms
  • hide

    the everyday opposite for keeping something unknown

  • conceal

    slightly more formal and often deliberate

Grammar Patterns

betray + secret/plan

betray + object + to + listener

betray + place/information

Usage Note

Object is usually a secret, plan, hiding place, date, or other hidden fact. Distinguish from sense 4, where what becomes visible is a feeling or quality rather than information.

Common Mistakes

She betrayed me the secret at lunch.
She betrayed the secret to me at lunch.
the secret is the direct object; the listener comes after 'to'.
The note betrayed about the plan.
The note betrayed the plan.
do not add 'about' when the hidden information is the object.

4. to let a feeling, thought, or personal quality become visible even though you ar

4.verbtransitiveB2
Definition

to let a feeling, thought, or personal quality become visible even though you are trying not to show it.

Example

Her shaking hands betrayed her fear during the job interview.

body sign + betray + feeling

A small smile betrayed how proud the coach felt.

betray how + adjective-clause

Common collocations
  • betray fear
  • betray anger
  • betray pride
  • betray nervousness
Synonyms
  • show

    the broad everyday verb, but less specific about accidental display

  • reveal

    slightly stronger and can be more general than this emotional sense

  • give away

    informal and often used for signs that accidentally show the truth

  • signal

    focuses on indicating something, often through a sign or expression

Antonyms
  • hide

    the common opposite for keeping feelings or qualities unseen

  • mask

    stresses deliberately covering what you feel or are like

Grammar Patterns

betray + feeling

betray how + adjective-clause

body part/voice + betray + emotion

Usage Note

The subject is often something visible or audible, such as hands, eyes, a face, a smile, or a voice. Distinguish from sense 3, which is about making information known rather than showing an emotion or quality.

Common Mistakes

His eyes betrayed that he was tired.
His eyes betrayed his tiredness.
this sense more naturally takes a feeling or quality as the object.
The smile betrayed happy.
The smile betrayed happiness.
use a noun object after 'betray', not an adjective alone.

Word family

  • betrayal
    nounC1
  • betrayer
    nounC2

Synonym discussion

Sense: verb/1

'Betray' is strongest when someone turns against a person, group, or country that trusted them. 'Deceive' focuses on making someone believe something false, so it does not always involve loyalty. 'Abandon' stresses leaving someone without help, but not necessarily joining the other side. 'Inform on' is narrower and usually means telling the police or another authority about someone. 'Sell out' is informal and adds the idea of acting for money or advantage. You can abandon a friend by walking away, inform on a classmate by naming them, or deceive a customer with false claims, but betray suggests a deeper break of loyalty: 'The spy betrayed his country' and 'She felt betrayed by her oldest friend.'

betray ↗deceive ↗abandon ↗inform on ↗sell out ↗

Common collocations

Nouns

Adverbs

Phrases

  • feel betrayed
  • betray someone's trust

Prepositions

Etymology

LatinFrenchEnglish

English 'betray' came through French from a Latin verb meaning 'hand over' or 'deliver'. That older idea of giving someone over to another side helps explain why the word first centered on treachery and later widened to include breaking trust, revealing secrets, and accidentally showing feelings.