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
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Pygmalion
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Word Warriors: Four Years of Words Worth Reviving
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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:
The Federal Bureau of Investigation trains its agents to notice common signs of mendacity in the people they interrogate: a raised eyebrow, a subtle wince.
From The Wall Street Journal ● Sep. 15, 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
McAfee wrote that “an odor of mendacity remains.”
From Seattle Times ● Jun. 3, 2024
This theme of mendacity and impenitence ran throughout Engoron’s ruling.
From Slate ● Feb. 16, 2024
We know merely what disasters his mendacity occasioned.
From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume II: The Kingdom on the Waves" by M.T. Anderson
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
Putney was there with his wife, and Lyra regretful of her lightness, and Mrs. Munger repentant of her mendacities.
From Annie Kilburn : a Novel by William Dean Howells
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions 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.
