Meaning & Definition
adjective
Based on a mistaken belief; misleading or deceptive.
His argument was fallacious, relying on false premises to draw his conclusion.
Characterized by fallacy or error in reasoning.
The fallacious logic in her statement made it difficult to take her seriously.
Illogical, unsound.
The fallacious nature of the claim was exposed after thorough investigation.
Containing a fallacy; deceptive.
She pointed out the fallacious assumptions in the research study.
Etymology
From Latin 'fallax' (deceitful), from 'fallere' (to deceive).
Common Phrases and Expressions
fallacious reasoning:
Reasoning that is based on a fallacy or error in logic.
fallacious argument:
An argument that contains a fallacy or is logically unsound.
Slang Meanings
BS
That whole presentation was just BS; it was completely fallacious.
fake news
The article was just fallacious claims and fake news.