n.
Pronunciation: ' fa-l ə -s ē
Function: noun
Inflected Form: plural -cies
Etymology: Latin fallacia, from fallac-, fallax deceitful, from fallere to deceive
Date: 14th century
1 a obsolete : GUILE , TRICKERY b : deceptive appearance : DECEPTION
2 a : a false or mistaken idea <popular fallacies > b : erroneous character : ERRONEOUSNESS
3 : an often plausible argument using false or invalid inference