noun
-
the tendency to be untruthful
-
a falsehood
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of mendacity
1640–50; < Late Latin mendācitās falsehood, equivalent to Latin mendāci- (stem of mendāx ) given to lying, false + -tās -ty 2
Explanation
Mendacity is a tendency to lie. Your friend might swear that he didn't eat your secret chocolate stash, but you'll find it hard to believe him if he's known for his mendacity. Anyone in the habit of lying frequently has the characteristic of mendacity. People often accuse government officials of mendacity, or being less than honest. You're bound to get frustrated by the mendacity of your friend who's a pathological liar. Mendacity comes from the Latin root word mendacium, or "lie." Don't confuse mendacity with a similar-sounding word, audacity — which means "fearlessness, daring, or bravery."
Vocabulary lists containing mendacity
A Web of Lies
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Pygmalion
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Word Warriors: Four Years of Words Worth Reviving
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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:
A few chapters occupy his immediate point of view, but the novel never tries to explain his mendacity and lack of feeling.
From The Wall Street Journal ● Mar. 26, 2026
He may invite passionate opposition from his foes, but his fans simply shrug at his misstatements, malapropisms and mendacity.
From Los Angeles Times ● Jul. 30, 2024
“However, an odor of mendacity remains,” the judge wrote.
From Seattle Times ● Mar. 15, 2024
This theme of mendacity and impenitence ran throughout Engoron’s ruling.
From Slate ● Feb. 16, 2024
If divorce had presented itself as the dastardly antithesis of all this, it could easily have been cast onto the other pan of the scales, along with betrayal, illness, thieving, assault and mendacity.
From "Atonement" by Ian McEwan
That irks the panelists, too, evidenced in a shot of Wilson rolling his eyes at one of Coulter’s kookier mendacities.
From Salon ● Oct. 22, 2025
Wedgwood wrote about the moral and ethical deficiencies and mendacities of the figures involved in the Thirty Years War and the English Civil War.
From Washington Post ● Sep. 15, 2020
Reading from a carefully worded script, McMaster strung together a series of mendacities and half-truths that appalled his friends and admirers.
From Slate ● Mar. 16, 2018
This theme returned passionately in the countercultural '60s, when inarticulate sincerity seemed the answer to the state's mendacities.
From Time Magazine Archive
Any attempt to summarise their mendacities would be foredoomed to failure; the output of rumours would exceed the limits of an ordinary tome.
From The Siege of Kimberley by Phelan, T.
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.
