de·​lu·​sion | \ di-ˈlü-zhən How to pronounce delusion (audio) , dē- \

Definition of delusion

1a : something that is falsely or delusively believed or propagated under the delusion that they will finish on schedule delusions of grandeur
b psychology : a persistent false psychotic belief regarding the self or persons or objects outside the self that is maintained despite indisputable evidence to the contrary the delusion that someone was out to hurt him also : the abnormal state marked by such beliefs
2 : the act of tricking or deceiving someone : the state of being deluded … accused the Bohemian of having practised the most abominable arts of delusion among the younger brethren.— Walter Scott

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Other Words from delusion

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

Choose the Right Synonym for delusion

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 delusion in a Sentence

He has delusions about how much money he can make at that job. He is living under the delusion that he is incapable of making mistakes. She is under the delusion that we will finish on time. As the illness progressed, his delusions took over and he had violent outbursts.
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Recent Examples on the Web Jack is in his Woodside apartment, in the throes of a delusion. New York Times, "The Epicenter," 3 Dec. 2020 In an essay at Jewish Currents that’s at once hilarious and terrifying, Tanner explores this bizarre, mad world: one of mass delusion and conspiracy theories. Cheri Lucas Rowlands, Longreads, "The Mormon Mommy Bloggers of Instagram," 25 Dec. 2020 From the beginning, the delusion of American individualism and the angst of an uncertain end date have blocked hordes of people from realizing or acknowledging that there is only one safe way to do this. Casey Taylor, The New Republic, "Inside the Hostage Crisis of America’s Dying Restaurants," 11 Dec. 2020 There is no time left for more debate, delay or delusion. David Dworkin For Cnn Business Perspectives, CNN, "Pelosi and McConnell need to make a stimulus deal to protect renters," 8 Dec. 2020 With that in mind, Popovich and others associated with the NBA are under no delusion that the 72-game regular season will go off without a hitch. Jeff Mcdonald,, "Popovich: Personal responsibility paramount as Spurs set for camp opener," 1 Dec. 2020 And with post-election division fueled by delusion and demagoguery, this Turkey Day was poised to be a bloodbath. Petula Dvorak, Washington Post, "Will covid-19 make this the Turkey Day without political fights?," 23 Nov. 2020 Those keywords — delusion, justice, accountability and freedom — name and organize the four short essays that provide most of the book’s pages. Washington Post, "Delusions, justice, accountability and freedom in America," 18 Dec. 2020 The dream of making it as actor requires optimism at a level that frequently borders on delusion. al, "Former Opelika, Clemson football player Jock McKissic finds role in drama ‘Your Honor’," 17 Dec. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'delusion.' 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 delusion

15th century, in the meaning defined at sense 2

History and Etymology for delusion

Middle English, from Late Latin delusion-, delusio, from deludere — see delude

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Time Traveler for delusion

Time Traveler

The first known use of delusion was in the 15th century

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Statistics for delusion

Last Updated

18 Jan 2021

Cite this Entry

“Delusion.” Dictionary, Merriam-Webster, Accessed 26 Jan. 2021.

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More Definitions for delusion


How to pronounce delusion (audio)

English Language Learners Definition of delusion

: a belief that is not true : a false idea
: a false idea or belief that is caused by mental illness


de·​lu·​sion | \ di-ˈlü-zhən How to pronounce delusion (audio) \

Kids Definition of delusion

: a false belief that continues in spite of the facts “You might be laboring under the delusion that the entire … world is impressed with you …”— J. K. Rowling, Goblet of Fire


de·​lu·​sion | \ di-ˈlü-zhən How to pronounce delusion (audio) \

Medical Definition of delusion

1a : the act of deluding : the state of being deluded
b : an abnormal mental state characterized by the occurrence of psychotic delusions
2 : a false belief regarding the self or persons or objects outside the self that persists despite the facts and occurs in some psychotic states — compare hallucination sense 1, illusion sense 2a

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