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

Definition of hallucination

  1. 1a :  perception of objects with no reality usually arising from disorder of the nervous system or in response to drugs (as LSD) was having hallucinationsb :  the object so perceived wasn't sure if the rain was real or a hallucination

  2. 2 :  an unfounded or mistaken impression or notion :  delusion

Examples of hallucination in a sentence

  1. He could not tell if what he was seeing was real or if it was a hallucination.

  2. He has been having hallucinations due to the medication.

Origin and Etymology of hallucination

see hallucinate

First Known Use: 1629

Synonym Discussion of 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.

HALLUCINATION Defined for English Language Learners


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

Definition of hallucination for English Language Learners

  • : 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

HALLUCINATION Defined for Kids


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

Definition of hallucination for Students

  1. :  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

Medical Dictionary


noun hal·lu·ci·na·tion \hə-ˌlüs-ən-ˈā-shən\

Medical Definition of hallucination

  1. 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 2, illusion 2a

  2. 2:  the object of a hallucinatory perception

Seen and Heard

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a brief usually trivial fact

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