(not in technical use as a medical diagnosis) not sane; not of sound mind; mentally deranged.
of, relating to, or characteristic of a person who is mentally deranged: a wild and insane look on her face.
Law. considered to be or to have been affected with insanity, and therefore lacking legal responsibility or legal capacity: The judge deemed him criminally insane on the basis of his delusions and hallucinations.
temporarily unable to think clearly: I think I'm going insane from all the noise outside.
utterly senseless: an insane plan.
Slang. excessive or extravagant; extreme: This much snow in April is just insane!
Slang. astonishingly great; wonderful: Without his insane performance, the film would've been a total flop.
- in·sane·ly, adverb
- in·sane·ness, noun
- pseu·do·in·sane, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use insane in a sentence
One question I asked him was whether he considered himself clinically insane.Can I Ask You a Ridiculously Personal Question? (Ep. 451) | Stephen J. Dubner | February 11, 2021 | Freakonomics
It was insane how quickly this post spread and people started sharing with each other.How One Instagram Post Inspired Diners From Around the World to Donate Restaurant Meals | Amanda Kludt | January 27, 2021 | Eater
To better position your title tag, use high impact, power words like best, exclusive, insane, and so on.Five hacks to enhance your organic CTR and rankings in SERPs | Karl Tablante | January 27, 2021 | Search Engine Watch
It’s insane to me that I am still told by some nurses that they have to reuse their masks for two weeks.“We’ve Let the Worst Happen”: Reflecting on 400,000 Dead | by Logan Jaffe | January 23, 2021 | ProPublica
The sea shanty arose midway through the last millennium as a breed of work-song for sailors to while away the time, forge communal bonds, and generally keep from going insane.Sea shanties show TikTok is the global proving grounds for culture | Robert Hackett | January 19, 2021 | Fortune
After all, what says Christmas more than obligations, gastrointestinal distress, and insane dining companions?
Yet she spoke of his dignity in such an insane situation and when she touched on his pain she expressed her own on his behalf.The Life and Hard Times Of The Family A Cuban Defector Left Behind | Brin-Jonathan Butler | December 19, 2014 | THE DAILY BEAST
It's insane that you are losing friends in real life because of their ignorance on the Internet.
“It's insane to see what the extreme version of that type of helpless anger combined with mental illness can create,” Cook wrote.
Now we need to change the insane policies that lead to his killing.Eric Garner Was Choked to Death for Selling Loosies | Nick Gillespie | December 3, 2014 | THE DAILY BEAST
After an hour's insane remonstrance, he gave in to his own alarm, rather than to the persuasion of his partner.
The attitude of the nineteenth century upon this point was little short of insane.The Unsolved Riddle of Social Justice | Stephen Leacock
Some corporations are still denied voluntary action, as well as minors and insane persons.
It is not quite so easy to state rules that apply to insane persons because their conditions vary so greatly.
And again when an insane man has made a contract, the relief to which he is entitled depends on circumstances.
British Dictionary definitions for insane
mentally deranged; crazy; of unsound mind
(as collective noun; preceded by the): the insane
characteristic of a person of unsound mind: an insane stare
irresponsible; very foolish; stupid
- insanely, adverb
- insaneness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012