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delusion

noun

de·lu·siondi-ˈlü-zhən How to pronounce delusion (audio)

dē-

Synonyms ofdelusion next

:something that is falsely or delusively believed orpropagated

under thedelusion that they will finish on schedule

delusions of grandeur

psychology:a persistent falsepsychotic belief regarding the self or persons or objects outside the self that is maintained despite indisputable evidence to the contrary

thedelusion that someone was out to hurt him

also:the abnormal state marked by such beliefs

:the act of tricking or deceiving someone:the state of beingdeluded

… accused the Bohemian of having practised the most abominable arts ofdelusion among the younger brethren.—

Walter Scott

delusional

di-ˈlüzh-nəl How to pronounce delusion (audio)

dē-

-ˈlü-zhə-nᵊl

adjective

delusionary

di-ˈlü-zhə-ˌner-ē How to pronounce delusion (audio)

dē-

adjective

Synonyms

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Choose the Right Synonym fordelusion

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.

anillusion of safety

hallucination implies impressions that are the product of disordered senses, as because of mental illness or drugs.

suffered from terrifyinghallucinations

mirage in its extended sense applies to an illusory vision, dream, hope, or aim.

claimed a balanced budget is amirage

Examples ofdelusion in a Sentence

He hasdelusions about how much money he can make at that job. He is livingunder the delusion that he is incapable of making mistakes. She isunder the delusion that we will finish on time. As the illness progressed, hisdelusions took over and he had violent outbursts.

Recent Examples on the Web

Examples are automatically compiled from online sources to show current usage.Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.Send us feedback.

The private and personalized nature of AI use makes its mental health impact difficult to track, but the evidence of potential harms is mounting, from professional apathy to attachments to new forms ofdelusion.—

Parmy Olson,Mercury News, 12 July 2025At his trial, Fish's children described a chaotic home life marked by erratic behavior, religiousdelusionsand violence.—

Christina Coulter,People.com, 12 July 2025The Leaders Who Listen Win In The Long RunCultures that survive and thrive are those that invite disagreement, reward constructive tension and embrace data overdelusion.—

Oscar Chavez-Arrieta,Forbes.com, 20 June 2025Researchers noted the positive effects of ecstatic epilepsy and synthesized fifty-three theoretical models ofdelusion.—

Rafil Kroll-Zaidi,Harpers Magazine, 21 June 2025See All Example Sentences fordelusion

Word History

Etymology

Middle Englishdilusioun "deceit," borrowed from Late Latindēlūsiōn-, dēlūsiō "trickery, deceiving," from Latindēlūdere "to deceive, dupe" +-tiōn-, -tiō, suffix of verbal action — more atdelude

First Known Use

15th century, in the meaning defined atsense 2

Time Traveler

The first known use ofdelusion was in the 15th century

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Phrases Containingdelusion

Rhymes fordelusion

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Browse Nearby Words

delundung

delusion

delusionist

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Articles Related todelusion

delulu

Delusional; audaciously self-confident

Delusion vs. Hallucination: An...

'Allusion' vs. 'Illusion'

Let there be no delusion

Cite this Entry

Style

“Delusion.”Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/delusion. Accessed 18 Jul. 2025.

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Kids Definition

delusion

noun

de·lu·siondi-ˈlü-zhən How to pronounce delusion (audio)

:the act of deluding:the state of being deluded

:a mistaken or misleading belief

:a false belief that persists despite evidence proving it false and occurs especially in some mentally disturbed states

delusional

-ˈlüzh-nəl How to pronounce delusion (audio)

-ən-ᵊl

adjective

Medical Definition

delusion

noun

de·lu·siondi-ˈlü-zhən How to pronounce delusion (audio)

:the act ofdeluding:the state of beingdeluded

:an abnormal mental state characterized by the occurrence of psychotic delusions

:a false belief regarding the self or persons or objects outside the self that persists despite the facts and occurs in some psychotic states comparehallucinationsense 1,illusionsense 2a