treachery
gb/tɹˈɛt͡ʃɚi/ us/tɹˈɛt͡ʃɚi/
C1
English
~ 5400
Senses
0 senses
Noun
C1
action
1
betrayal of trust or loyalty
The act of hurting someone who trusted you, by not being loyal to them.
Usage pattern:
an act of treachery by [someone] against [someone/something]
Common mistake:
Learners sometimes confuse "treachery" with "trickery." "Treachery" is about disloyalty and betrayal of trust, while "trickery" is about using clever lies or tricks to fool someone, not necessarily breaking a relationship of trust. Learners may also overuse "treason" when they mean general personal betrayal; "treason" usually refers specifically to betrayal of a country or government.
Synonyms
betrayal (More common and slightly broader; can be emotional or personal without sounding as strong or dramatic as "treachery.")
|
treason (Usually used for serious betrayal against one's country or government, often with a legal meaning.)
|
perfidy (A formal/literary word stressing deliberate, cold-hearted betrayal.)
Antonyms
loyalty (Emphasizes strong support and faithfulness instead of betrayal.)
|
faithfulness (Focuses on staying true to someone or something over time.)
Collocations
an act of treachery
|betrayal and treachery
|political treachery
|personal treachery
|accused of treachery
|guilty of treachery
Themes
relationships
|politics
|emotions
|core_vocabulary
Examples
- His decision to sell company secrets was seen as a shocking act of treachery.
- She never forgave her friend for the treachery of revealing her darkest secret.
- History remembers his signature on the enemy treaty as pure treachery.
- The general was executed for treachery after secretly helping the opposing army.
- In the novel, the hero is destroyed by the treachery of his most trusted advisor.
Learner examples
- He felt deep pain after his brother's treachery.
- Telling the enemy our plan would be treachery.
- The king punished the man for his treachery.
- Her treachery broke the team's trust.
- They called his move an act of treachery.
Noun
literary
C1
property
2
deceptive and hidden danger
The way something is secretly dangerous, even if it looks safe.
Usage pattern:
the treachery of [something]
Common mistake:
Learners often think "treachery" must always involve people. In this sense, it is used for things like sea, weather, roads, or memory that seem safe but are actually dangerous or misleading. It is also more common in written or literary English than in everyday speech.
Synonyms
deceptiveness (Neutral term focusing on how appearances mislead; less emotional or dramatic than "treachery.")
|
peril (Focuses on danger itself, not necessarily that the danger is hidden or misleading.)
Antonyms
safety (Highlights the absence of danger, in contrast to the hidden danger implied by "treachery.")
|
reliability (Stresses that something behaves as expected, rather than suddenly becoming dangerous.)
Collocations
the treachery of the sea
|the treachery of the ice
|the treachery of the roads
|the treachery of memory
|hidden treachery
|the treachery of the slopes
Themes
nature
|safety
|travel
|core_vocabulary
Examples
- Sailors feared the treachery of the reef, which lay just below the calm surface of the water.
- They underestimated the treachery of the mountain path and were caught in a sudden rockslide.
- The documentary showed the treachery of thin ice that looks solid but breaks without warning.
- Writers often describe the treachery of the desert sun, which slowly weakens travelers.
- He warned us about the treachery of memory, which can quietly change details over time.
Learner examples
- The treachery of the river surprised the new swimmers.
- We did not see the treachery of the road until the car slid on the black ice.
- Hikers must respect the treachery of the high mountains.
- The captain knew the treachery of these waters.
- The teacher spoke about the treachery of memory in old age.
Grammar
Dictionary form
treachery
IPA
GB/tɹˈɛt͡ʃɚi/
US/tɹˈɛt͡ʃɚi/
Syllables & stress
treach - ery (2 syllables)
Stress on 1st syllable (treach)
Word forms
Noun
- Base: treachery
- Plural: treacheries, treachery
Word family
Forms
treacheries
noun
Core family
treacherous
adjective B2
treacherously
adverb C1
Advanced or less common
traitorous
adjective
Expressions
accused of treachery
1/əkjˈuzd əv tɹˈɛt͡ʃɚi/
fixed phrase
said to have committed treachery
Used when people say someone has done treachery, often in a serious or official way.
Examples
- Several officers were accused of treachery after the failed coup.
- Anyone who questioned the leader was quickly accused of treachery.
an act of treachery
1/ən ˈækt əv tɹˈɛt͡ʃɚi/
fixed phrase
a single event of betrayal
One specific action where someone is not loyal and hurts a person or group that trusted them.
Examples
- Handing over the secret documents was an act of treachery.
- The coach called leaving the team before the final an unforgivable act of treachery.
betrayal and treachery
1/bɪtɹˈeɪəl ˈænd tɹˈɛt͡ʃɚi/
fixed phrase
disloyalty and serious betrayal
Strong language used to talk about people being very disloyal and breaking trust in a serious way.
Examples
- The film is a dark story of love, betrayal and treachery.
- Newspapers described the scandal as a tale of betrayal and treachery at the highest level.
guilty of treachery
1/ɡˈɪlti əv tɹˈɛt͡ʃɚi/
fixed phrase
having committed an act of treachery
Used when someone is said to really have done treachery, not just been accused of it.
Examples
- He was found guilty of treachery and sentenced to life in prison.
- History has judged him guilty of treachery against his own people.
treachery and deceit
1/tɹˈɛt͡ʃɚi ˈænd dɪsˈit/
fixed phrase
betrayal together with dishonesty
A phrase that talks about both strong betrayal and lying or cheating.
Examples
- The novel follows a family destroyed by treachery and deceit.
- The report exposed years of treachery and deceit inside the company.