Meaning & use
treacherous
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Meanings
adjectivecomparable
Dangerous in a way that is not obvious, with hidden risks that can trap you.
Grammar: Describes roads, weather, water or ground: treacherous conditions.
Patterns
- treacherous conditions
- a treacherous road
The icy road was treacherous after the storm.
Hikers avoided the treacherous mountain path.
Strong currents make the beach treacherous for swimmers.
adjectivecomparable
Likely to betray trust or be disloyal.
Grammar: Describes people or actions that break faith.
Patterns
- a treacherous friend
- a treacherous act
The king executed his treacherous advisor.
She felt hurt by his treacherous behavior.
A treacherous ally sold the plans to the enemy.
adjectivecomparablefigurative
Not to be trusted because it seems safe but is likely to fail or mislead.
Grammar: Often figurative: treacherous memory.
Patterns
- a treacherous memory
Memory can be treacherous after many years.
The calm market proved treacherous for new investors.
Her treacherous knee gave way on the stairs.
Word forms
| comparative | more treacherous |
|---|---|
| superlative | most treacherous |
Common combinations
- treacherous conditions
- Drivers faced treacherous conditions on the icy highway.
- treacherous waters
- The sailors crossed treacherous waters near the rocks.
- a treacherous path
- The treacherous path along the cliff was closed.
- a treacherous act
- Selling the secret plans was a treacherous act.
- treacherous terrain
- The vehicle struggled over treacherous terrain.
Synonyms and how they differ
- hazardous
- Hazardous is more formal and can describe any danger, whereas treacherous implies a hidden or sneaky danger.
- perilous
- Perilous is more literary and stresses serious danger.
- disloyal
- Disloyal describes someone who fails to support others, while treacherous suggests a serious, often secret, betrayal.
- deceitful
- Deceitful focuses on lying, whereas treacherous focuses on betraying trust.
Opposites
Word family
- treachery noun
- the act of betraying trust
- treacherously adverb
- in a disloyal or dangerous way
- treacherousness noun
- the quality of being dangerous or disloyal
- traitor noun
- a person who betrays a country or group
Commonly confused: treacherous or treasonous?
treacherous vs treasonous
Treasonous means involving treason against a country, which is narrower than treacherous.
Practice
The road was ___ in winter because of hidden patches of ice.
Choose one answer.
Treacherous means dangerous in a hidden way, which fits hidden ice. Tedious, timid and tolerant do not describe a road.
Make it your own
Write a sentence using “treacherous”, then check it and compare it with the examples above.