Simple Definition of fallacy
: a wrong belief : a false or mistaken idea
: the quality of being false or wrong
Examples of fallacy
The fallacy of their ideas about medicine soon became apparent.
<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
Rhymes with fallacy
Seen and Heard
What made you want to look up fallacy? Please tell us where you read or heard it (including the quote, if possible).