insanity

noun

in·san·i·ty | \ in-ˈsa-nə-tē

plural insanities

Definition of insanity

1 dated : a severely disordered state of the mind usually occurring as a specific disorder

2 law : unsoundness of mind or lack of the ability to understand that prevents one from having the mental capacity required by law to enter into a particular relationship, status, or transaction or that releases one from criminal or civil responsibility

3a : extreme folly or unreasonableness the insanity of violence His comments were pure insanity.

b : something utterly foolish or unreasonable the insanities of modern life

Synonyms & Antonyms On the Meaning of Insanity More Example Sentences Learn More about insanity

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Synonyms & Antonyms for insanity

Synonyms

aberration, dementia, derangement, lunacy, madness, mania, rage [archaic]

Antonyms

mind, saneness, sanity

On the Meaning of Insanity

An oft-quoted bon mot (frequently attributed to Albert Einstein, Benjamin Franklin, or a number of other people who probably never said it) is that insanity may be defined as “doing the same thing over and over and expecting different results.” While the job of lexicographers might be easier if they were allowed to use witty sayings instead of precise definitions, such belletristic labors are not within their purview. The straight facts about insanity are these: it has been in use in English since the late 16th century, for the first two hundred years or so carrying only the literal meaning “the condition of being mentally deranged.” In the 19th century it began to take on a looser sense, “extreme folly or unreasonableness.” In modern usage, insanity may be found in both senses: you may tell your brother that trying to skateboard while holding onto a car is "insanity" (in which case you mean that it is extremely foolish) or encounter the stricter original meaning in such contexts as insanity plea.

Examples of insanity in a Sentence

She was found not guilty by reason of insanity. His friends thought his decision to quit his job was pure insanity. Please, no more violence. It's time to stop this insanity. the insanities of modern life

Recent Examples on the Web

Kahler argues Kansas law unconstitutionally prevented him from using an insanity defense. — USA TODAY, "Saving whales, Manson murder house: News from around our 50 states," 17 July 2019 Competency proceedings are different than pleading not guilty by reason of insanity. — Megan Cassidy, SFChronicle.com, "Doctor finds Nia Wilson’s alleged killer at BART station fit to stand trial," 17 July 2019 The defense considered mounting an insanity defense, but after evaluating the possible outcome Rich opted for a guilty plea and prison to be followed by parole and treatment, Stawicki said. — David Owens, courant.com, "Granby man pleads guilty to stabbing parents," 10 July 2019 Ramos, 39, has pleaded not guilty and not criminally responsible, Maryland’s version of an insanity defense. — Brian Witte, BostonGlobe.com, "Judge orders holding newspaper shooting trial in 2 phases," 25 June 2019 And Burns’ trial, for which Lee decamped south, didn’t disappoint: amid fervid legal sparring, Radney’s daring insanity defense prevailed — Burns was consigned to a psychiatric hospital from which within weeks he was discharged. — Stephen Phillips, latimes.com, "This Southern murder trial inspired Harper Lee's 'lost' book. 'Furious Hours' reexamines it," 14 June 2019 Jurors who convicted him rejected the insanity defense. — Jeff Truesdell, PEOPLE.com, "Despite Plea by Ex-Wife to Spare His Life, S.C. Man Who Killed Their 5 Kids Is Sentenced to Death," 13 June 2019 The idea was a mix of folly and insanity—as is obvious now and should’ve been obvious then. — Colin Dickey, The New Republic, "The Secrets in Greenland’s Ice," 11 July 2019 Instead, Caracci threw the ball to home and all insanity broke loose. — Andrew Joseph, For The Win, "Ole Miss pitcher's ill-advised toss to home turned into a shocking 2-run error," 24 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'insanity.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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More Definitions for insanity

insanity

noun

English Language Learners Definition of insanity

: severe mental illness : the condition of being insane

: something that is very foolish or unreasonable

See the full definition for insanity in the English Language Learners Dictionary

insanity

noun

in·san·i·ty | \ in-ˈsa-nə-tē

Kids Definition of insanity

: the condition of being abnormal or unhealthy in mind

insanity

noun

in·san·i·ty | \ in-ˈsan-ət-ē

plural insanities

Medical Definition of insanity

1 dated : a severely disordered state of the mind usually occurring as a specific disorder

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insanity

noun

in·san·i·ty

Legal Definition of insanity

1 : unsoundness of mind or lack of the ability to understand that prevents one from having the mental capacity required by law to enter into a particular relationship, status, or transaction or that releases one from criminal or civil responsibility: as

a : a disease, defect, or condition of the mind that renders one unable to understand the nature of a criminal act or the fact that it is wrong or to conform one's conduct to the requirements of the law being violated

b : inability to understand and participate in legal proceedings brought against one : incompetence

insanity

Definition of insanity

Synonyms & Antonyms for insanity

On the Meaning of Insanity

Examples of insanity in a Sentence

First Known Use of insanity

English Language Learners Definition of insanity

Kids Definition of insanity

Medical Definition of insanity

Legal Definition of insanity

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