perfidy
Americannoun
-
deliberate breach of faith or trust; faithlessness; treachery.
perfidy that goes unpunished.
-
an act or instance of faithlessness or treachery.
noun
Synonym Usage
See disloyalty.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of perfidy
1585–95; < Latin perfidia faithlessness, equivalent to perfid ( us ) faithless, literally, through (i.e., beyond the limits of ) faith ( per- per- + fid ( ēs ) faith + -us adj. suffix) + -ia -y 3
Explanation
If you shared your most embarrassing secrets with a friend who then told them to everyone he knows, his betrayal could be described as perfidy. The noun perfidy means "deceitfulness" or "treachery," so it's not just being mean, but deliberately betraying a trust. The Latin root of perfidy is made up of per, or "through," and fidem, or "faith." So in order for perfidy to happen, there has to have first been a sense of faith in place, which was then broken or betrayed.
Vocabulary lists containing perfidy
The Declaration of Independence
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A Web of Lies
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Excerpt from "The Declaration of Independence"
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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.
See Examples For:
He has persisted in insulting the leaders of these countries for failing to bail him out of his jam, writing long screeds on social media that rail against their alleged perfidy.
From Salon ● Mar. 19, 2026
Unaware of Samary’s perfidy, Gomina, 50, ordered Samary to meet him at QRF headquarters to organize a team to rescue Issa and his family.
From The Wall Street Journal ● Mar. 12, 2026
Now, those who are convinced of the perfidy of cats won’t like the answers that are emerging.
From New York Times ● Nov. 12, 2022
For many older Russians, memories of World War II consist mainly of Western perfidy and Russian indomitability.
From Washington Post ● Apr. 12, 2022
And the owners of them, sullen faced, unrepentant, pushed by the Eyes against the walls of their bedrooms, while the sorrowful voice of the announcer tells us voice-over about their perfidy and ungratefulness.
From "The Handmaid's Tale" by Margaret Atwood
A famous essay in the Baffler, “The Problem With Music,” laid out the perfidies of the major-label system, at the time still in a post-Nirvana feeding frenzy for young rock acts.
From Los Angeles Times ● May 8, 2024
Swinton Byrne’s own reactions to her fictional lover’s perfidies were more indignant, and less compliant, than what we see onscreen as Julie’s.
From The New Yorker ● May 13, 2019
Gathering up great and infamous political speeches, his juxtapositions compare and contrast passions and perfidies with subtlety and wit, ranging across the French, Flemish, American and German tongues.
From The Guardian ● Aug. 27, 2012
You saved this worst stroke for the last; This crowns your perfidies, and ruins me.
From Tartuffe Or, the Hypocrite by Page, Curtis Hidden
Its snares and perfidies never come to an end.
From The Man Who Laughs by Hugo, Victor
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.
