insanity

noun
in·​san·​i·​ty | \ in-ˈsa-nə-tē How to pronounce insanity (audio) \
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

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Synonyms & Antonyms for insanity

Synonyms

Antonyms

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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
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Recent Examples on the Web The latter term is Maryland's version of an insanity defense. NBC News, "Man accused in Maryland newspaper shooting that killed 5 changes plea to guilty," 28 Oct. 2019 Justices will also consider cases that involve several aspects of defendants’ rights: whether criminal convictions require a unanimous jury, minors can be given a life sentence and a state can abolish the insanity defense. Morgan Marietta, The Conversation, "This year at the Supreme Court: Gay rights, gun rights and Native rights," 3 Oct. 2019 For Trump to attempt to create an island of gas-guzzling inefficiency in a sea of increasingly efficient zero-emission cars is insanity. San Diego Union-Tribune, "California, China to team up on climate research institute," 23 Sep. 2019 There have been some wild games in the Pac-12 in recent years — some fine examples of pinball football — Cal 60, WSU 59 comes to mind — but this was next-level insanity. Because of the total points (previous conference record: 127). Jon Wilner, The Mercury News, "Saturday Night Five: Eating your own, three for the price of two, more officiating controversy — in the Pac-12, it’s called Saturday," 22 Sep. 2019 There have been some wild games in the Pac-12 in recent years — some fine examples of pinball football — Cal 60, WSU 59 comes to mind — but this was next-level insanity. Because of the total points (previous conference record: 127). Jon Wilner, The Denver Post, "Pac-12 football rewind: Eating your own, three for the price of two, more officiating controversy — in Conference of Champions it’s called Saturday," 22 Sep. 2019 Cases with an insanity defense are split into two portions: the guilt phase, and the sanity phase. Nate Gartrell, The Mercury News, "‘I too have forgiven’: In plea deal, East Bay murder defendant found not guilty by reason of insanity," 15 Sep. 2019 While Republicans have been busy planting the seeds of their likely doom, the Texas Democratic Party has been rebuilding itself into a force capable of capitalizing on its opponents’ strategic insanity. Bob Moser, The New Republic, "Texas Is Bracing for a Blue Wave in 2020. Yes, Texas.," 12 Aug. 2019 After hearing Bobby openly admit his insanity, Rebecca does the only thing there is to do: Dump the madman. Elena Nicolaou, refinery29.com, "Billions Season 4 Finale Recap: Et Tu, Bobby?," 4 June 2019

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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First Known Use of insanity

1590, in the meaning defined at sense 1

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Statistics for insanity

Last Updated

13 Nov 2019

Time Traveler for insanity

The first known use of insanity was in 1590

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More Definitions for insanity

insanity

noun
How to pronounce insanity (audio)

English Language Learners Definition of insanity

: severe mental illness : the condition of being insane
: something that is very foolish or unreasonable

insanity

noun
in·​san·​i·​ty | \ in-ˈsa-nə-tē How to pronounce insanity (audio) \

Kids Definition of insanity

: the condition of being abnormal or unhealthy in mind

insanity

noun
in·​san·​i·​ty | \ in-ˈsan-ət-ē How to pronounce insanity (audio) \
plural insanities

Medical 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

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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
c : inability to understand the nature and purpose of a punishment (as the death penalty) to which one has been sentenced
d : inability to understand the nature and consequences of one's acts (as making a will) or of events, matters, or proceedings in which one is involved — see also commitment, durham rule, irresistible impulse test, m'naghten test, not guilty by reason of insanity, substantial capacity test — compare capacity, competency, competent, diminished capacity, sanity
2 : the affirmative defense of having acted while insane

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Comments on insanity

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