Define what a fallacy is in general.

A fallacy is a mistaken belief, especially one based on unsound arguments. It is a deceptive or misleading argument that is logically unsound. Fallacies can be used intentionally to manipulate or deceive others, or they can be unintentional errors in reasoning. Common types of fallacies include ad hominem attacks, straw man arguments, and appeals to emotion.

A fallacy is a flaw in reasoning. It can be a misleading or deceptive argument that appears to be valid but is actually not. Fallacies can be used intentionally to deceive or unintentionally to make a mistake in reasoning.