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

Keep scrolling for more

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

Fortunately, people don’t experience the hallucinations as being frightening. Andrea K. Mcdaniels, baltimoresun.com, "Ask the Expert: Macular degeneration can lead to difficulty reading, recognizing faces and performing other fine tasks," 17 Apr. 2018 Studies have shown that bereaved people can experience grief hallucinations, and there are concerns that interacting with avatars might raise the risk. David Cox /, NBC News, "Will 'digital resurrections' let us bring back the dead?," 16 Apr. 2018 The main focus of his new religion focused on mediumship, and the ability to experience unconscious hallucinations and attain clairvoyance. Sarah Betancourt, Longreads, "The Religion No One Talks About: My Search For Answers in an Old Caribbean Faith," 30 Mar. 2018 Harlan saw Peters briefly early the next morning in the emergency room and again later that morning while Peters was experiencing hallucinations, the suit says. Matt Campbell, kansascity, "Lawsuit says doctor wouldn’t check for what killed his patient: Meningitis," 20 Feb. 2018 When Bernard has his final hallucination of Robert by the seashore, the old master tells his student that the splendor of the seas dwarf all of humankind’s great magic. Josephine Livingstone, The New Republic, "Puzzled by Westworld? Look to Shakespeare.," 26 June 2018 Connecting the two, or conveying accurately our own personal hallucination to someone else, is the central problem of being human. Adam Rogers, WIRED, "The Fundamental Nihilism of Yanny vs. Laurel," 16 May 2018 Nuplazid, a drug for hallucinations and delusions associated with Parkinson’s disease, failed two clinical trials. Caroline Chen, Fox News, "FDA repays drug industry by rushing risky meds to market," 1 July 2018 Dunn has been diagnosed with schizoaffective disorder, a mental health condition characterized by hallucinations and delusions. Keith Bierygolick, Cincinnati.com, "Why did Ohio man hold woman captive in Blanchester shed? An imaginary prostitution ring.," 14 June 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.

See More

First Known Use of hallucination

1629, in the meaning defined at sense 1a

History and Etymology for hallucination

see hallucinate

Keep scrolling for more

Learn More about hallucination

Share hallucination

Statistics for hallucination

Last Updated

19 Sep 2018

Look-up Popularity

Time Traveler for hallucination

The first known use of hallucination was in 1629

See more words from the same year

Keep scrolling for more

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

Keep scrolling for more

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).


by word of mouth

Get Word of the Day daily email!

Test Your Vocabulary

Name that Food Quiz

How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!