hal·​lu·​ci·​na·​tion | \ hə-ˌlü-sə-ˈnā-shən How to pronounce hallucination (audio) \

Definition of hallucination

1a : perception of objects with no reality usually arising from disorder of the nervous system or in response to drugs (such as LSD) was having hallucinations
b : the object so perceived wasn't sure if the rain was real or a hallucination
2 : an unfounded or mistaken impression or notion : delusion

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Choose the Right Synonym for hallucination

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

Examples of hallucination in a Sentence

He could not tell if what he was seeing was real or if it was a hallucination. He has been having hallucinations due to the medication.

Recent Examples on the Web

Its first scene is an extended hallucination in which Peter Ksander’s set, goosed by Keith Skretch’s video, appears to flicker and spasm. New York Times, "Review: ‘This Was the End,’ a Spectral Riff on Chekhov," 10 June 2018 Signs of a marijuana overdose could include a rapid heart rate, hallucinations, vomiting, panic attacks and paranoia. Everton Bailey Jr., OregonLive.com, "Oregon mom cited after toddler overdoses on marijuana-infused candy," 31 May 2018 For nine years of highs and lows, Doug and his wife sought medical opinions in Texas and elsewhere to help Patrick shed the hallucinations and delusions of schizophrenia. Charlotte Huff, Washington Post, "Alarming Suicide Rate Jolts Texas Community Into Action," 7 May 2018 Stimulation of another brain area caused him to experience an hallucination. Suzanne O’sullivan, WSJ, "Confessions of the Miswired Brain," 5 Oct. 2018 Certain symptoms, such as feeling agitated and having hallucinations, usually go away within days of starting an antipsychotic medication. Kasandra Brabaw, SELF, "7 Myths You Might Believe About Antipsychotic Medications," 7 Dec. 2018 Of course, the audience knows this is all a hallucination and that Nell is actually dancing away to her doom. Alex Abad-santos, Vox, "How Netflix’s The Haunting of Hill House uses color to underscore its horror," 26 Oct. 2018 Exhibitions are on semi-annual rotation: The current show has 40 paper works of Kusama's hallucinations and runs through August 31; the next will focus on plants. Meredith Carey, Condé Nast Traveler, "Where to See Yayoi Kusama's Art Across the U.S.," 27 July 2018 Someone experiencing psychosis has difficulty understanding what is real and usually experiences delusions (false beliefs) and hallucinations (seeing or hearing things that aren’t there). Carolyn L. Todd, SELF, "9 Things You Should Know About Taking Antipsychotic Drugs," 7 Dec. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'hallucination.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of hallucination

1629, in the meaning defined at sense 1a

History and Etymology for hallucination

see hallucinate

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Statistics for hallucination

Last Updated

30 May 2019

Look-up Popularity

Time Traveler for hallucination

The first known use of hallucination was in 1629

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More Definitions for hallucination



English Language Learners Definition of hallucination

: something (such as an image, a sound, or a smell) that seems real but does not really exist and that is usually caused by mental illness or the effect of a drug


hal·​lu·​ci·​na·​tion | \ hə-ˌlü-sə-ˈnā-shən How to pronounce hallucination (audio) \

Kids Definition of hallucination

: the seeing of objects or the experiencing of feelings that are not real but are usually the result of mental disorder or the effect of a drug


hal·​lu·​ci·​na·​tion | \ hə-ˌlüs-ᵊn-ˈā-shən How to pronounce hallucination (audio) \

Medical Definition of hallucination

1 : a perception of something (as a visual image or a sound) with no external cause usually arising from a disorder of the nervous system (as in delirium tremens or in functional psychosis without known neurological disease) or in response to drugs (as LSD) — compare delusion sense 2, illusion sense 2a
2 : the object of a hallucinatory perception

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Comments on hallucination

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


to move with exaggerated bouncy motions

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