Fallacy
Etymology
From Latin "fallacia" (deceit, trick), from "fallax" (deceptive), from "fallere" (to deceive, to cause to fall) — the same root behind fail, false, and fault. A fallacy is a snare that trips reasoning up; the deception can even fool the person committing it.
noun · /FAL-uh-see/
A flaw in reasoning that makes an argument invalid or misleading even when it sounds convincing.
What it names
A handle for a recurring reasoning trap — a pattern of bad inference common enough to have earned a name.
Example
Assuming the crime rate rose because ice-cream sales rose is a textbook fallacy.
Related idea
Distinguish it from a falsehood: a falsehood is a claim that happens to be untrue; a fallacy is a broken way of getting to a claim. An argument riddled with fallacies can still stumble onto a true conclusion — the reasoning is what’s bad, not necessarily the answer.