noun fal·la·cy \ˈfa-lə-sē\

: a wrong belief : a false or mistaken idea

: the quality of being false or wrong

plural fal·la·cies

Full Definition of FALLACY

a obsolete :  guile, trickery
b :  deceptive appearance :  deception
a :  a false or mistaken idea <popular fallacies>
b :  erroneous character :  erroneousness
:  an often plausible argument using false or invalid inference

Examples of FALLACY

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

Origin of FALLACY

Latin fallacia, from fallac-, fallax deceitful, from fallere to deceive
First Known Use: 14th century

Other Logic Terms

a posteriori, connotation, corollary, inference, mutually exclusive, paradox, postulate, syllogism

Rhymes with FALLACY

FALLACIES Defined for Kids


noun fal·la·cy \ˈfa-lə-sē\
plural fal·la·cies

Definition of FALLACY for Kids

:  a false or mistaken idea
:  false reasoning
July 29, 2015
indomitable Hear it
incapable of being subdued or conquered
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