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optical illusion

See more synonyms for optical illusion on Thesaurus.com
noun
  1. See under illusion(def 4).

Origin of optical illusion

First recorded in 1785–95

illusion

[ih-loo-zhuhn]
noun
  1. something that deceives by producing a false or misleading impression of reality.
  2. the state or condition of being deceived; misapprehension.
  3. an instance of being deceived.
  4. Psychology. a perception, as of visual stimuli (optical illusion), that represents what is perceived in a way different from the way it is in reality.
  5. a very thin, delicate tulle of silk or nylon having a cobwebbed appearance, for trimmings, veilings, and the like.
  6. Obsolete. the act of deceiving; deception; delusion.

Origin of illusion

1300–50; Middle English < Latin illūsiōn- (stem of illūsiō) irony, mocking, equivalent to illūs(us) past participle of illūdere to mock, ridicule (il- il-1 + lūd- play (see ludicrous) + -tus past participle suffix, with dt > s) + -iōn- -ion
Related formsil·lu·sioned, adjective
Can be confusedallusion delusion elusion hallucination illusion (see synonym study at the current entry)

Synonyms for illusion

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1. aberration, fantasy, chimera. illusion, hallucination, delusion refer to false perceptions or ideas. An illusion is a false mental image produced by misinterpretation of things that actually exist: A mirage is an illusion produced by reflection of light against the sky. A hallucination is a perception of a thing or quality that has no physical counterpart: Under the influence of LSD, Terry had hallucinations that the living-room floor was rippling. A delusion is a persistent false belief: A paranoiac has delusions of persecution.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for optical illusion

apparition, hallucination, illusion, mirage, phantasm, specter, vision, phantasmagoria

Examples from the Web for optical illusion

Historical Examples of optical illusion

British Dictionary definitions for optical illusion

optical illusion

noun
  1. an object causing a false visual impression
  2. an instance of deception by such an object

illusion

noun
  1. a false appearance or deceptive impression of realitythe mirror gives an illusion of depth
  2. a false or misleading perception or belief; delusionhe has the illusion that he is really clever
  3. psychol a perception that is not true to reality, having been altered subjectively in some way in the mind of the perceiverSee also hallucination
  4. a very fine gauze or tulle used for trimmings, veils, etc
Derived Formsillusionary or illusional, adjectiveillusioned, adjective

Word Origin for illusion

C14: from Latin illūsiō deceit, from illūdere; see illude
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for optical illusion

illusion

n.

mid-14c., "act of deception," from Old French illusion "a mocking, deceit, deception" (12c.), from Latin illusionem (nominative illusio) "a mocking, jesting, irony," from illudere "mock at," literally "to play with," from assimilated form of in- "at, upon" (see in- (2)) + ludere "to play" (see ludicrous). Sense of "deceptive appearance" developed in Church Latin and was attested in English by late 14c. Related: Illusioned "full of illusions" (1920).

Online Etymology Dictionary, © 2010 Douglas Harper
optical illusion in Medicine

illusion

[ĭ-lōō′zhən]
n.
  1. An erroneous perception of reality.
  2. An erroneous concept or belief.
  3. The condition of being deceived by a false perception or belief.
  4. Something, such as a fantastic plan or desire, that causes an erroneous belief or perception.
Related formsil•lu′sion•al null adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.