in·sane | \(ˌ)in-ˈsān \

Definition of insane 

1a(1) : exhibiting a severely disordered state of mind : affected with mental illness

(2) law : affected with insanity (see insanity sense 2) criminally insane

b : unable to think in a clear or sensible way : crazy insane with jealousy not used technically

2 : used by, typical of, or intended for mentally ill people an insane asylum

3 : absurd an insane scheme for making money

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Other Words from insane

insanely adverb
insaneness \(ˌ)in-ˈsān-nəs \ noun

Examples of insane in a Sentence

The murderer was found to be criminally insane. She was insane with jealousy. He had an insane look in his eyes. She likes to drive at insane speeds. He had this insane idea that he could get rich by selling old computers.
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Recent Examples on the Web

People still use their feet to crush grapes to make port, isn’t that insane? Natalie B. Compton, GQ, "Four Bottles of Booze That Make for Easy, High-Reward Father's Day Presents," 12 June 2018 My daughter is going to go crazy just like you because her mother is insane. Alexa Tsoulis-reay, The Cut, "I Was Convinced I Might Kill My Child," 31 May 2018 In an administration notable for bizarre economic policies, this was among the most insane. Marc Levinson, WSJ, "‘Magic Bean’ Review: A Legume’s World Conquest," 3 June 2018 Click through to find some of season 2's most insane moments., "Every Insane Thing That Has Happened This Season On Riverdale," 17 May 2018 The Volvo Ocean Race is the world’s most insane sporting event, a 52,000-mile, round-the-world race that takes eight months to complete. Paul Brady, Condé Nast Traveler, "How to See Newport, Rhode Island, According to Two Volvo Ocean Race Sailors," 8 May 2018 Ruud had won two gold medals in the Olympics’ most insane and dangerous sport. Michael S. Rosenwald, Washington Post, "The insanity of ski jumping: Where on earth did this sport come from?," 15 Feb. 2018 The plot may be as indecipherable as The Big Sleep, but the action is insane in this sixth installment of Mission: Impossible. Aja Hoggatt,, "Critics are loving Mission: Impossible -- Fallout," 12 July 2018 A few years later, the Avengers side of things is even more insane. Sam Machkovech, Ars Technica, "Ant-Man and the Wasp review: Even smaller scale, even bigger heart," 6 July 2018

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

circa 1550, in the meaning defined at sense 1

History and Etymology for insane

Latin insanus, from in- + sanus sane

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Phrases Related to insane

go insane

insane asylum

the insane

Statistics for insane

Last Updated

16 Sep 2018

Look-up Popularity

Time Traveler for insane

The first known use of insane was circa 1550

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More Definitions for insane


in·sane | \in-ˈsān \

Kids Definition of insane

1 : not normal or healthy in mind

2 : used by or for people who are insane an insane asylum

3 : very foolish or unreasonable

Other Words from insane

insanely adverb


in·sane | \(ˈ)in-ˈsān \

Medical Definition of insane 


1 : exhibiting a severely disordered state of mind

2 : used by, typical of, or intended for insane persons an insane asylum

Other Words from insane

insanely adverb



Legal Definition of insane 

: affected with insanity

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More from Merriam-Webster on insane

Thesaurus: All synonyms and antonyms for insane

Spanish Central: Translation of insane

Nglish: Translation of insane for Spanish Speakers

Britannica English: Translation of insane for Arabic Speakers

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