(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. afflicted with insanity and 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.
Origin of insane
First recorded in 1550–60; from Latin insānus “unsound (of mind), demented, frenzied”; see origin at in-3, sane
The pandemic has changed the way we view the many previously held ways of doing things, which has led to some insane gains in certain stocks that have been able to capitalize.
Why even the best stocks have to crash|Ben Carlson|September 13, 2020|Fortune
There’s an insane amount of talent out there, and I’m pleased to see the demand grow as couples become more educated about what wedding photography can be.
Couples spend thousands on a wedding photographer for that perfect shot|Rachel King|September 6, 2020|Fortune
With everyone getting into meditation as we all slowly go insane and the world ends, this Muse headband monitors your brain activity while you meditate and produces customized soundscapes to keep you centered.
This Weekend: A Sangria Slushie Summer|Fiona Zublin|August 7, 2020|Ozy
After all, what says Christmas more than obligations, gastrointestinal distress, and insane dining companions?
The Top 10 Nontraditional Christmas TV Episodes|Jace Lacob|December 25, 2014|DAILY BEAST
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|DAILY BEAST
It's insane that you are losing friends in real life because of their ignorance on the Internet.
The Unbearable Whiteness of Protesting|Rawiya Kameir, Judnick Mayard|December 10, 2014|DAILY BEAST
“It's insane to see what the extreme version of that type of helpless anger combined with mental illness can create,” Cook wrote.
School Shooters Love This Pickup Artist Website|Brandy Zadrozny|December 5, 2014|DAILY BEAST
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|DAILY BEAST
From fancying herself neglected by her husband she became jealous of him—a most absurd and insane idea.
The Young People's Wesley|W. McDonald
Of course I at once sent for old Dr. Macnab, and asked him to fetch a certificate for an insane person with him.
Scotch Wit and Humor|W. H. (Walter Henry) Howe
He tried Hawaii, where, unable to prove him insane, the authorities deported him.
The Cruise of the Snark|Jack London
The only way to combat these conditions in the city is to have strict registration of all feeble-minded and insane.
The Eugenic Marriage, Volume I. (of IV.)|W. Grant Hague, M.D.
Honora, in spite of her discomfort, had an insane desire to giggle.
A Modern Chronicle, Complete|Winston Churchill
British Dictionary definitions for insane
insane
/ (ɪnˈseɪn) /
adjective
mentally deranged; crazy; of unsound mind
(as collective noun; preceded by the)the insane
characteristic of a person of unsound mindan insane stare