English Reference
noun

fallacy

n.
US /ˈfæɫəsi/ UK /fˈæləsi/ fal·la·cy UK spelling fallacies, fallacy's

  1. 01 C1 Advanced Academic

    an idea that many people believe is true, but is actually false.

    a widely held but false belief or misconception.

    Simple

    It is a common fallacy that eating carrots will give you perfect night vision.

    In context

    The documentary aims to expose the fallacy that economic growth can continue indefinitely without environmental consequences.

    Usage

    Often used with the adjective 'common' or 'popular'.

  2. 02 C1 Advanced AcademicTechnical Law

    a mistake in an argument that makes the conclusion wrong.

    a failure in reasoning which renders an argument invalid; a specious or deceptive argument.

    Simple

    The lawyer pointed out the fallacy in the witness's logic.

    In context

    His entire thesis rests on a logical fallacy, assuming that because two events happened together, one must have caused the other.

    Usage

    Frequently appears in the phrase 'logical fallacy'.

    sophistrycasuistryflaw

From Middle English fallaci, fallace, fallas, from Old French fallace, from Latin fallācia (“deception, deceit”), from fallāx (“deceptive, deceitful”), from fallere (“to deceive”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin fallācia
Level C1 · Advanced
Frequency Frequent
Updated