fallacy

noun

fal·la·cy ˈfa-lə-sē

plural fallacies

Synonyms of fallacy next

: a false or mistaken idea

popular fallacies

prone to perpetrate the fallacy of equating threat with capability—

C. S. Gray

: erroneous character : erroneousness

The fallacy of their ideas about medicine soon became apparent.

: deceptive appearance : deception

obsolete : guile, trickery

: an often plausible argument using false or invalid inference

Did you know?

Philosophers are constantly using the word fallacy. For them, a fallacy is reasoning that comes to a conclusion without the evidence to support it. This may have to do with pure logic, with the assumptions that the argument is based on, or with the way words are used, especially if they don't keep exactly the same meaning throughout the argument. There are many classic fallacies that occur again and again through the centuries and everywhere in the world. You may have heard of such fallacies as the "ad hominem" fallacy, the "question-begging" fallacy, the "straw man" fallacy, the "slippery slope" fallacy, the "gambler's" fallacy, or the "red herring" fallacy. Look them up and see if you've ever been guilty of any of them.

Examples of fallacy in a Sentence

The fallacy of their ideas about medicine soon became apparent. the once-common fallacy that girls just weren't any good at math

Recent Examples on the Web For some, rap is considered a gauche genre that cannot be taken seriously in the pop culture lexicon, but these key looks prove that, that notion is merely a fallacy. —

Robyn Mowatt, Essence, 22 Aug. 2023 Without safeguards, this new minstrelsy will produce the inverse effect of the post-racial fallacy peddled during the Obama years. —

Jason Parham, WIRED, 21 July 2023 Every smug undergraduate exposé of a fallacy would be immediately countered with a robust defense of Aristotle’s reasoning. —

Nikhil Krishnan, The New Yorker, 26 June 2023 The fundamental fallacy at the heart of the No Labels effort is that there is no difference between the Republican and Democratic parties—that both favor extremists. —

Sue Halpern, The New Yorker, 29 June 2023 From watching companies go through ups and downs throughout my career, my top pieces of advice are: Be aware of and avoid common cash management fallacies, know your position in the different stages of a disruption if one occurs, and inculcate cash-conscious behavior into your company. —

Lee Henderson, Forbes, 20 Apr. 2023 The overwhelming success of Black Panther helped dismantle the long-standing Hollywood fallacy that, while the world would willingly pay to cycle through seven variations of Batman, no one could make money with a true Dark Knight. —

Eisa Nefertari Ulen, The Hollywood Reporter, 13 June 2023 Murray's second contract was the sunk cost fallacy run amok. —

Jeremy Cluff, The Arizona Republic, 5 June 2023 The play’s Oakland residents argue about colorism, assimilation and the fallacies of trusting the system, embodying the tensions that propelled Newton’s broader ideologies about Blackness. —

Naveen Kumar, New York Times, 2 June 2023 See More

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