treachery

American  

[trech-uh-ree] / ˈtrɛtʃ ə ri /

noun

• treacheries
  plural

1. violation of faith; betrayal of trust; treason.

   Antonyms:

   loyalty

2. an act of perfidy, faithlessness, or treason.

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treachery British  

/ ˈtrɛtʃərɪ /

noun

1. the act or an instance of wilful betrayal

2. the disposition to betray

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Synonym Usage

See disloyalty.

Other Word Forms

Noun Inflected Forms

• treacheries
  plural

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.

Example Sentences

See Examples For:

treachery treacheries

First released in 2005, the series has previously followed the story of Greek god Kratos and the triumphs, tragedies and treachery he experiences.

From BBC ● Jun. 3, 2026

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

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

“I am one of the few the Dark Lord has told. Nevertheless, had I not been in on the secret, Narcissa, you would have been guilty of great treachery to the Dark Lord.”

From "Harry Potter and the Half-Blood Prince" by J.K. Rowling

Le Pen alliances are famously rocky, and the family’s treacheries have for decades delighted the French media.

From New York Times ● Mar. 31, 2022

“There are treacheries and enmities in abundance against me. Joan Sumner is now claiming she never agreed to marry me. She complains that I have claimed to be richer than I am.”

From New York Times ● Sep. 8, 2016

Conrad’s bleak treacheries and Buchan’s sour anomie became grist to le Carré’s genius.

From The Guardian ● Oct. 17, 2015

Along the eastern shore of Nantucket, exposed to the delights and treacheries of the Atlantic, lies Sankaty Head.

From Golf Digest ● Nov. 3, 2014

Washington simply did not have control of the government and was inadvertently lending credibility to the treacheries being hatched all around him.

From "Founding Brothers: The Revolutionary Generation" by Joseph J. Ellis

Related Words

• betrayal
• infidelity
• treason