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noun il·lu·sion \i-ˈlü-zhən\

Simple Definition of illusion

  • : something that looks or seems different from what it is : something that is false or not real but that seems to be true or real

  • : an incorrect idea : an idea that is based on something that is not true

Source: Merriam-Webster's Learner's Dictionary

Full Definition of illusion

  1. 1 a obsolete :  the action of deceiving b (1) :  the state or fact of being intellectually deceived or misled :  misapprehension (2) :  an instance of such deception

  2. 2 a (1) :  a misleading image presented to the vision (2) :  something that deceives or misleads intellectually b (1) :  perception of something objectively existing in such a way as to cause misinterpretation of its actual nature (2) :  hallucination 1 (3) :  a pattern capable of reversible perspective

  3. 3 :  a fine plain transparent bobbinet or tulle usually made of silk and used for veils, trimmings, and dresses


play \-ˈlüzh-nəl, -ˈlü-zhə-nəl\ adjective

Examples of illusion in a sentence

  1. The video game is designed to give the illusion that you are in control of an airplane.

  2. They used paint to create the illusion of metal.

  3. She says that all progress is just an illusion.

allusion and illusion

Allusion and illusion may share some portion of their ancestry (both words come in part from the Latin word ludere, meaning “to play”), and sound quite similar, but they are distinct words with very different meanings. An allusion is an indirect reference, whereas an illusion is something that is unreal or incorrect. Each of the nouns has a related verb form: allude “to refer indirectly to,” and illude (not a very common word), which may mean “to delude or deceive” or “to subject to an illusion.”

Illustration of illusion

Origin and Etymology of illusion

Middle English, from Anglo-French, from Late Latin illusion-, illusio, from Latin, action of mocking, from illudere to mock at, from in- + ludere to play, mock — more at ludicrous

First Known Use: 14th century

Synonym Discussion of illusion

delusion, illusion, hallucination, mirage mean something that is believed to be true or real but that is actually false or unreal. delusion implies an inability to distinguish between what is real and what only seems to be real, often as the result of a disordered state of mind <delusions of persecution>. illusion implies a false ascribing of reality based on what one sees or imagines <an illusion of safety>. hallucination implies impressions that are the product of disordered senses, as because of mental illness or drugs <suffered from terrifying hallucinations>. mirage in its extended sense applies to an illusory vision, dream, hope, or aim <claimed a balanced budget is a mirage>.

ILLUSION Defined for Kids


noun il·lu·sion \i-ˈlü-zhən\

Definition of illusion for Students

  1. 1 :  something that is false or unreal but seems to be true or real <The video game creates the illusion of flying.>

  2. 2 :  a mistaken idea <She had no illusions about her chances of winning.>

Medical Dictionary


noun il·lu·sion \il-ˈü-zhən\

Medical Definition of illusion

  1. 1:  a misleading image presented as a visual stimulus

  2. 2a:  perception of something objectively existing in such a way as to cause misinterpretation of its actual nature; especially :  optical illusion—compare delusion 2b:  hallucination 1c:  a pattern capable of reversible perspective


\-ˈüzh-nəl, -ən-əl\play adjective

Seen and Heard

What made you want to look up illusion? Please tell us where you read or heard it (including the quote, if possible).


a sculptured or ornamented band

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