fallacy

[ fal-uh-see ]

/ ˈfæl ə si /

SEE MORE SYNONYMS FOR fallacy ON THESAURUS.COM

noun, plural fal·la·cies.

a deceptive, misleading, or false notion, belief, etc.: That the world is flat was at one time a popular fallacy.

a misleading or unsound argument.

deceptive, misleading, or false nature; erroneousness.

Logic. any of various types of erroneous reasoning that render arguments logically unsound.

Obsolete. deception.

Nearby words

Origin of fallacy

1350–1400; < Latin fallācia a trick, deceit, equivalent to fallāc- (stem of fallāx) deceitful, fallacious + -ia -y³; replacing Middle English fallace < Middle French

SYNONYMS FOR fallacy

1. misconception, delusion, misapprehension.

SEE MORE SYNONYMS FOR fallacy ON THESAURUS.COM

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fallacy

In fact, what this map really showed was the fallacy of aggregates – and how statistics can mask real cultural shifts.
Beer Countries vs. Wine Countries|Clive Irving|December 7, 2014|DAILY BEAST
Every time the thermometer drops, another anti-science politician mocks climate change as a fallacy.
From Snowy Atlanta to Sunny Sochi, It's All About Global Weirding|Scott Bixby|February 12, 2014|DAILY BEAST
To prove the fallacy of said cargo cult, Olson goes into the numbers.
The GOP's Socially Conservative Minority Voter Cargo Cult|Justin Green|December 15, 2012|DAILY BEAST
The many who believe that human knowledge begins in the academy are guilty of the fallacy of “lecturing birds on how to fly.”
A Manifesto for Disorder: Nassim Nicholas Taleb’s ‘Antifragile’ Reviewed|Robert Herritt|November 26, 2012|DAILY BEAST

Which brings me to the real point here: the entire premise of Mr. Rubin's moral question is built upon a fallacy.
A Sophistic Moral Case For War|Ali Gharib|October 27, 2012|DAILY BEAST
An example of this fallacy is the popular error that strong drink must be a cause of strength.
A System of Logic: Ratiocinative and Inductive|John Stuart Mill
The fallacy of such a contention seems too evident to call for argument.
Principles of Teaching|Adam S. Bennion
From her we had inherited the fallacy that man was made for the world, not the world for man.
All Roads Lead to Calvary|Jerome K. Jerome
The common sense of the world always rejects this gross fallacy.
Diderot and the Encyclopaedists (Vol 1 of 2)|John Morley
The "ethicist's fallacy" is the source of all absolutism in theory, and all intolerance in practice.
The Philosophy of Spinoza|Baruch de Spinoza

British Dictionary definitions for fallacy

fallacy

/ (ˈfæləsɪ) /

noun plural -cies

an incorrect or misleading notion or opinion based on inaccurate facts or invalid reasoning

unsound or invalid reasoning

the tendency to mislead

logic an error in reasoning that renders an argument logically invalid

Word Origin for fallacy

C15: from Latin fallācia, from fallax deceitful, from fallere to deceive

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for fallacy

fallacy

late 15c., "deception, false statement," from Latin fallacia "deception," noun of quality from fallax (genitive fallacis) "deceptive," from fallere "deceive" (see fail (v.)). Specific sense in logic dates from 1550s. An earlier form was fallace (c.1300), from Old French fallace.

Culture definitions for fallacy

fallacy

A false or mistaken idea based on faulty knowledge or reasoning. For example, kings who have divorced their wives for failing to produce a son have held to the fallacy that a mother determines the sex of a child, when actually the father does. (See sex chromosomes.)

fallacy

noun, plural fal·la·cies.

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Origin of fallacy

Examples from the Web for fallacy

fallacy

noun plural -cies

Word Origin for fallacy

fallacy

fallacy