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

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.
Recent Examples on the Web In Brazil, like the United States, the idea that the voting system is routinely manipulated by corrupt officials and unscrupulous partisans has become a delusion of the febrile right-wing hive mind. Andre Pagliarini, The New Republic, 27 July 2022 Of all the crises of the Cold War and Civil Rights riots and the Vietnam War, nothing compares to the delusion and lack of belief of the centre values of democracy, and elections, and integrity about science and experts. Steve Baltin, Forbes, 17 Apr. 2022 China and Russia should be wary of the mutual delusion of backing only by the ruble and the yuan. Andy Kessler, WSJ, 13 Mar. 2022 Few novelists are better than Perrotta at conveying the full spectrum of human delusion. Tom Perrotta, New York Times, 31 May 2022 This sky-is-falling delusion, particularly from leaders with access to classified intelligence, is at best counterproductive and at worst dangerous. Fox News, 25 Apr. 2022 Putin’s key delusion is his willful failure to understand—and accept—how Ukraine has come to be. Tarik Cyril Amar, Time, 4 Mar. 2022 Inventing Anna is really an exploration of one determined woman's delusion. Christopher Rosa, Glamour, 10 Feb. 2022 That’s because Republicans labor under the delusion that the 2020 election was stolen. New York Times, 17 Mar. 2022 See More

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.

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

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Last Updated

10 Aug 2022

Cite this Entry

“Delusion.” Dictionary, Merriam-Webster, Accessed 12 Aug. 2022.

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More Definitions for delusion


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, Harry Potter and the 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

More from Merriam-Webster on delusion

Nglish: Translation of delusion for Spanish Speakers

Britannica English: Translation of delusion for Arabic Speakers Encyclopedia article about delusion


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