hal·​lu·​ci·​na·​tion | \hə-ˌlü-sə-ˈnā-shən \

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

For obvious reasons, Jack doesn’t share a lot of screen time with his adult children, but thanks to dream sequences and hallucinations there are rare exceptions. Emma Dibdin, Country Living, "'This Is Us' Recap: Jack and an Adult Kate Appeared Together for the First Time and It Was Emotional," 10 Oct. 2018 The temporal lobe’s role in memory suggests that the hallucination might have represented something from Donal’s past. Suzanne O’sullivan, WSJ, "Confessions of the Miswired Brain," 5 Oct. 2018 Meth is highly addictive and long-term use can cause violent behavior, paranoia and hallucinations. Alexis Stevens, ajc, "EXCLUSIVE: Majority of those killed by Georgia officers tested positive for drugs," 9 July 2018 The resulting intense hallucination led Muthart to gouge out her own eyes, using only her hands, while outside of a church in Anderson, South Carolina. Jason Duaine Hahn, PEOPLE.com, "Woman Who Gouged Out Her Own Eyes Opens Up 3 Months Later: I 'Feel Like Myself' Again," 30 May 2018 Hannah — the ghostly hallucination of her, anyway — is already with Clay. refinery29.com, "R29 Binge Club: 13 Reasons Why, Season 2," 18 May 2018 The hallucinations grew relentless, demanding that Gordon eat less, even stop touring. Patrick Flanary, Billboard, "Derek and the Dominos' Jim Gordon, Jailed for Killing His Mom, Denied Parole for Fear 'He'd Hurt Somebody Else'," 30 Apr. 2018 Hans Stegmeir's costumes are full of fancy; his snow-bunny outfit for the Antarctic hallucination must be seen to be fully appreciated. Tony Brown, charlotteobserver, "1996: 'Angels' is heavenly: Kudos to Charlotte Rep for tackling the work | Charlotte Observer," 30 Mar. 2018 For many who experience sleep paralysis, those hallucinations of demons and apparitions are not uncommon. Emma Goddard, Good Housekeeping, "What It's Really Like to Suffer From Sleep Paralysis," 21 Feb. 2016

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

14 Nov 2018

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 \

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 \

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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something that serves to warn or remind

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