fal·​la·​cious | \ fə-ˈlā-shəs How to pronounce fallacious (audio) \

Definition of fallacious

1 : embodying a fallacy a fallacious conclusion a fallacious argument
2 : tending to deceive or mislead : delusive false and fallacious hopes— Conyers Middleton

Other Words from fallacious

fallaciously adverb
fallaciousness noun

Did you know?

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 Followers of QAnon also regularly show up at events and successfully spread new fallacious claims. New York Times, 20 Dec. 2021 Cannabis as a gateway drug seems to be a hypothesis based on simplistic and fallacious logical processes. Dario Sabaghi, Forbes, 7 Dec. 2021 But this is based on the fallacious notion that depletion of the resource means ever-higher prices. Michael Lynch, Forbes, 5 Nov. 2021 The thinking that dominates the institution is fundamentally fallacious. Steve Forbes, Forbes, 16 Sep. 2021 Both were grounded on a fallacious interpretation of due process. Matthew J. Franck, National Review, 12 Sep. 2021 Thank goodness that investment bankers are constantly undoing the fallacious assumptions of an economic profession married to the belief that inflation is caused by too much investment. John Tamny, Forbes, 9 May 2021 Please keep all of this mind the next time some self-serious economist starts drooling about output gaps, overheating, and other fallacious notions so popular inside the economics profession. John Tamny, Forbes, 11 Apr. 2021 One of the more shallow and fallacious claims Padilla makes in the Times piece is that classicists and the field of classics share responsibility for the Capitol riot that took place on January 6th. Andre M. Archie, National Review, 27 Feb. 2021

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.

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First Known Use of fallacious

15th century, in the meaning defined at sense 1

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The first known use of fallacious was in the 15th century

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Last Updated

9 Jan 2022

Cite this Entry

“Fallacious.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fallacious. Accessed 20 Jan. 2022.

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More Definitions for fallacious



English Language Learners Definition of fallacious

: containing a mistake : not true or accurate

More from Merriam-Webster on fallacious

Nglish: Translation of fallacious for Spanish Speakers

Britannica English: Translation of fallacious for Arabic Speakers


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