men·​da·​cious men-ˈdā-shəs How to pronounce mendacious (audio)
: given to or characterized by deception or falsehood or divergence from absolute truth
mendacious tales of his adventures
mendaciously adverb
mendaciousness noun

Did you know?

Mendacious and lying have very similar meanings, but the two are not interchangeable. Mendacious is more formal and literary, suggesting a deception harmless enough to be considered somewhat bland. Lying is more blunt, accusatory, and often confrontational. You might yell, "You lying rat!" in an argument, but you would most likely stick to the more diplomatic, "Aren't you being somewhat mendacious?" in a business meeting. Mendacious can also imply habitual untruthfulness, whereas lying is more likely to be used to identify specific instances of dishonesty.

Choose the Right Synonym for mendacious

dishonest, deceitful, mendacious, untruthful mean unworthy of trust or belief.

dishonest implies a willful perversion of truth in order to deceive, cheat, or defraud.

a swindle usually involves two dishonest people

deceitful usually implies an intent to mislead and commonly suggests a false appearance or double-dealing.

the secret affairs of a deceitful spouse

mendacious may suggest bland or even harmlessly mischievous deceit and when used of people often suggests a habit of telling untruths.

mendacious tales of adventure

untruthful stresses a discrepancy between what is said and fact or reality.

an untruthful account of their actions

Examples of mendacious in a Sentence

Indeed, the racist and Malthusian elements in Darwin's work are subjects on which the new secularists are either silent, delicate, or mendacious. Eugene McCarraher, Commonweal, 15 June 2007
A choice item in the collection of mendacious stories that were circulated about Columbus after his death is this. Columbus lost himself on the way to Hispaniola, and only by virtue of letters and pilots sent by Martín Alonso did he manage to find the island and join Pinta. Samuel Eliot Morison, Admiral of the Ocean Sea, 1942
Mildred had become great friends with her and had given her an elaborate but mendacious account of the circumstances which had brought her to the pass she was in. W. Somerset Maugham, Of Human Bondage, 1915
The newspaper story was mendacious and hurtful. that tabloid routinely publishes the most moronically mendacious stories about celebrities
Recent Examples on the Web This is a crabbed and mendacious interpretation of the law. Michael Hiltzik, Los Angeles Times, 5 Apr. 2024 The administration of President Joe Biden has been steadfast in its refusal to criticize López Obrador’s security policies, avoiding confrontation even when the Mexican president has publicly attacked U.S. law-enforcement agencies as mendacious and corrupt. Tim Golden, ProPublica, 31 Jan. 2024 In the popular perception of the typical white-collar case, a judicious government prosecutes a mendacious executive on a mountain of incontrovertible evidence. Charles Gasparino, WSJ, 17 Dec. 2023 Nevertheless, the Court was emphatic that fraud is a financial crime, not a license for prosecutors to criminalize mendacious schemes to acquire or maintain such intangible benefits as political power. Andrew C. McCarthy, National Review, 16 Dec. 2023 Today, the challenges of wrestling with globalization, European integration, climate change, and migration favor mediocre and mendacious managers who inspire no one. Foreign Affairs, 12 Dec. 2023 But Tapper couldn’t keep Trump from veering off into mendacious accusations about the lawsuit and its plaintiffs, and Hillary Clinton and then-New York Atty. Michael Hiltzik, Los Angeles Times, 18 Sep. 2023 So why not just ignore this latest outburst from the mendacious Muscovite? Eric Berger, Ars Technica, 8 May 2023 Many less attractive traits are also recorded: Charles could be uncommunicative and dilatory, evasive and mendacious, refractory, vindictive, obstinate, even outright wicked, though self-delusive about the motives of others. R.j.w. Evans, The New York Review of Books, 11 June 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'mendacious.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


Latin mendac-, mendax — more at amend

First Known Use

1616, in the meaning defined above

Time Traveler
The first known use of mendacious was in 1616


Dictionary Entries Near mendacious

Cite this Entry

“Mendacious.” Dictionary, Merriam-Webster, Accessed 16 Jun. 2024.

Kids Definition


men·​da·​cious men-ˈdā-shəs How to pronounce mendacious (audio)
: apt to tell lies
mendaciously adverb

More from Merriam-Webster on mendacious

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!