Definition of insane in English:

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Pronunciation: /ɪnˈseɪn/


1In a state of mind which prevents normal perception, behaviour, or social interaction; seriously mentally ill: he had gone insane
More example sentences
  • And anyway, why would we consider Nietzsche's writings the product of an insane mind?
  • But them my parents would think I was mentally insane, and send me off to some special school.
  • It was one of those awkward silences that made me want to scream and break my mirror to prevent myself from going insane.
mentally ill, severely mentally disordered, of unsound mind, certifiable, psychotic, schizophrenic;
British  sectionable
British informal crackers, barmy, barking, barking mad, off one's trolley, round the twist, as daft as a brush, not the full shilling
North American informal buggy, nutsy, nutso, out of one's tree, wacko, squirrelly
Canadian & Australian/New Zealand informal bushed
New Zealand informal porangi
1.1(Of an action or quality) characterized or caused by madness: his eyes were glowing with insane fury
More example sentences
  • There was an insane feeding frenzy going on inside the reception tent.
  • He is propelled into an insane frenzy.
  • He lay on his back, knocked down by Michelle's flying fists that connected with his jaw in an insane fury.
1.2Extremely annoyed: a fly whose buzzing had been driving me insane
More example sentences
  • Utter failure to even attempt to play winning baseball drives me insane.
  • He's driving me insane!
  • He's going insane over questions being raised about his daughter's paternity.
mad, crazy;
angry, annoyed, irritated, cross, vexed, exasperated, incensed, enraged
British informal spare, crackers
1.3Extremely foolish; irrational: she had an insane desire to giggle
More example sentences
  • At the same time, all this does is alienate liberal supporters who are perplexed by her insane and pointless maneuvring.
  • For people to go out and say my agent made a mistake is utterly ridiculous and insane.
  • I am baffled at the ridiculous insane media coverage.
impracticable, untenable, implausible, unreasonable, irrational, illogical, unrealistic, unthinkable
informal potty, crazy, mad, off beam, way out, full of holes, cock-eyed
British informal daft, barmy
2 informal, chiefly US Shocking; outrageous: they were making insane amounts of money
More example sentences
  • It may escape the insane rental prices that typify so many New York neighborhoods.
  • Find a crazy low-budget horror director, shove insane amounts of money and creative control at them, and just let 'em make movies.
  • The idea of combining toys and games is brilliant, but those two properties are abusing it by charging insane prices.
2.1Astonishingly good or impressive; amazing: the peanut butter chocolate is insane
More example sentences
  • Sales have been insane and we have stepped up development to suit.
  • One of the big expenses comes from just how much insane detail they put in these high graphics games.
  • Check out some insane star trails in this time-lapse video of Death Valley.


Mid 16th century: from Latin insanus, from in- 'not' + sanus 'healthy'.

  • sanity from Late Middle English:

    Latin sanus meant ‘healthy’ which is the first recorded sense of sanity in English. Current meanings date from the early 17th century when sane was first recorded, although insane dates from the mid 16th century. Sanitary, sanitation, and sanatorium where you go to recover your health, all 19th century, come from the same root.

For editors and proofreaders

Line breaks: in¦sane

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