Definition of FALLACIOUS

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Oh what a tangled web we weave / When first we practise to deceive! So wrote Sir Walter Scott in his 1808 poem Marmion. Scott’s line wasn't written with etymology in mind, but it might be applied to the history of "fallacious." That word traces back to the Latin verb fallere ("to deceive"), but it passed through a tangle of Latin and French forms before it eventually made its way into English in the early 1500s. Other descendants of "fallere" in English include "fail," "false," and "fault."

Examples of fallacious in a Sentence

it's fallacious to say that something must exist because science hasn't proven its nonexistence consumers who harbor the fallacious belief that credit-card spending will never catch up with them

Recent Examples on the Web Yet this argument is not only improperly self-serving but also fallacious. — The Economist, "Britain and the European Union Boris Johnson’s government should prolong the Brexit transition," 11 June 2020 So my guess is that that ruling will be in favor of the aggrieved party in a fallacious ad. — Steven Levy, Wired, "Why Mark Zuckerberg’s Oversight Board May Kill His Political Ad Policy," 28 Jan. 2020 Clapper, Brennan, and the FBI helped to disseminate the fallacious Steele dossier to the press and among government agencies. — Victor Davis Hanson, National Review, "Former Intelligence Chiefs Fit Perfectly into Media Advocacy Culture," 19 Dec. 2019 But Democrats said that, too, was fallacious, noting that Mr. Trump allowed the aid to be delivered only after he had been briefed about the whistle-blower complaint. — Nicholas Fandos, New York Times, "House Panel Delays Vote on Impeachment Articles," 12 Dec. 2019 Ads that deploy fallacious reasoning and misrepresent the purpose of studies prey on the hopes and fears of patients, potentially subverting the integrity of informed consent. — Jonathan Kimmelman, STAT, "Cancer centers sell out science when they advertise clinical trials as treatment," 25 Apr. 2018 This word suggested a fallacious assumption: Poverty persisted only because of hitherto weak government resolve regarding the essence of war — marshalling material resources. — George Will, Alaska Dispatch News, "Old norms show a way out of poverty," 6 July 2017 But everyone's clinging to the fallacious belief that science just needs to be explained better and then people will change their minds. — Rebecca Onion, Slate Magazine, "The Angle: Bernie’s Pod Edition," 19 Apr. 2017 The thought that momentum carries over from game to game in the Stanley Cup playoffs is fallacious. — Eric Stephens, Orange County Register, "Leon Draisaitl’s hat trick, five points power Oilers to Game 6 rout of Ducks," 7 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fallacious.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.