delusion

noun

de·​lu·​sion di-ˈlü-zhən How to pronounce delusion (audio)
dē-
1
a
: 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
delusional
di-ˈlüzh-nəl How to pronounce delusion (audio)
dē-
-ˈlü-zhə-nᵊl
adjective
delusionary 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 The book cleverly draws you into the characters, motivations, and delusions of the founders of the Sullivan Institute, a radical community created in 1957 around an offshoot of psychoanalytic theory. Hannah E. Meyers, National Review, 10 Sep. 2023 For solace, give him only science fiction novels, superhero comics and a cadre of younger siblings and cousins to boss around, imbuing him with delusions of grandeur and a taste for unchecked power. Will Oremus, Washington Post, 10 Sep. 2023 Never has a stop so effectively demarcated the line between delusion, reality, and the liminal space in between. 7. Jessica Gentile, Vulture, 8 Sep. 2023 Lucas also recognized that sometimes waiting for the most unsettling symptoms of the disorder to emerge — the disturbing swirl of delusion and paranoia — often brought the best results. Thomas Curwen, Los Angeles Times, 8 Aug. 2023 Maybe a national trance would lift and the remaining dead-enders would shake their delusions. Vinson Cunningham, The New Yorker, 25 Aug. 2023 This is known as the delusion of expertise and can accelerate gambling behaviors and, ultimately, the development of a gambling addiction. Rachel Epstein, Men's Health, 22 Aug. 2023 The hatefulness culminated with an uprising at Capitol, with largely well to-do white people hopped up with rage and delusions to start a civil war against the non-Republican world on behalf of (and with the encouragement of) the former occupant of the White House. Malaika Jabali, Essence, 16 Aug. 2023 Mary Costantino was walking back to her car with a friend after a night out in Goose Hollow when a man experiencing a delusion threw a metal bottle at her head and knocked her out. oregonlive, 8 Aug. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'delusion.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 2

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

Dictionary Entries Near delusion

Cite this Entry

“Delusion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/delusion. Accessed 21 Sep. 2023.

Kids Definition

delusion

noun
de·​lu·​sion di-ˈlü-zhən How to pronounce delusion (audio)
1
: the act of deluding : the state of being deluded
2
a
: a mistaken or misleading belief
b
: 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·​sion di-ˈlü-zhən How to pronounce delusion (audio)
1
a
: 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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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