treachery
Americannoun
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violation of faith; betrayal of trust; treason.
- Antonyms:
- loyalty
-
an act of perfidy, faithlessness, or treason.
noun
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the act or an instance of wilful betrayal
-
the disposition to betray
Synonym Usage
See disloyalty.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of treachery
First recorded in 1175–1225; Middle English trecherie, from Middle French, Old French, from trech(ier) “to deceive” ( see trick) + -erie -ery
Explanation
Treachery is trickery, cheating, and deceit, like the treachery of your former friend who only stuck around until he stole your girlfriend and turned the whole grade against you. The noun treachery comes from the Old French word trechier, “to cheat.” Many a corrupt government or dictator has been accused of treachery: deceiving the people and abusing their trust. Greed is a common cause of treachery — with the promise of wealth, people can be tempted to betray their country and even their loved ones, as new celebrities find out when their best friends sell embarrassing secrets to the tabloids.
Vocabulary lists containing treachery
The Call of the Wild
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Franklin D. Roosevelt, "A Date That Will Live In Infamy" (1941)
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A Streetcar Named Desire
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Most of the unhappy denizens of Dante’s imagined hell are being eternally tormented for specific moral crimes in categories covering lust, gluttony, greed, anger, heresy, violence, fraud and treachery.
From Salon • Mar. 8, 2026
It’s a sprawling tale of divine corruption and human treachery that ends with the world being purified by fire and flood.
From The Wall Street Journal • Feb. 12, 2026
His treachery began in 1985 when he gave the Soviets the names of a few KGB officers secretly working for the FBI in exchange for $50,000.
From BBC • Jan. 6, 2026
Lizza, in his own statement, said: “Telling the truth is not harassment and accountability is not an ax, though I understand why Olivia finds it unpleasant to be confronted with her treachery and betrayal.”
From The Wall Street Journal • Dec. 4, 2025
They parted, she to the palace to weep over her treachery to her father, he to the ship to send two of his comrades for the dragon’s teeth.
From "Mythology: Timeless Tales of Gods and Heroes" by Edith Hamilton
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
