Definition of insanity in US English:



  • 1The state of being seriously mentally ill; madness.

    ‘he suffered from bouts of insanity’
    as complement ‘he attempted to plead insanity’
    • ‘The trial judge ruled that this was a defence of insanity, whereupon she pleaded guilty and appealed.’
    • ‘He had frequent bouts of insanity which allowed the structure of his government to be undermined.’
    • ‘He could easily slip into a state of insanity and attempt to commit suicide again.’
    • ‘This pathetic king regularly suffers bouts of insanity and is surrounded by usurpers!’
    • ‘I've seen it drive perfectly calm and contented people to temporary insanity and depression.’
    • ‘As well, he accuses a former lawyer of attempting to trick him into pleading insanity.’
    • ‘I would expect the defense to go that route, to plead not guilty by reason of insanity.’
    • ‘Humans are sociable things who like to communicate and being restricted like that affects people to the point of insanity.’
    • ‘He felt it spoke to him sometimes - call it insanity, call it depression, but he seriously felt that it did.’
    • ‘Since the average citizen is presumed to be sane, if they claim insanity, who decides?’
    • ‘It was seven short lines, and Claudia said she examined it closely for signs of insanity.’
    • ‘To me that is so disturbing that I think the case should be dismissed on the grounds of insanity.’
    • ‘Please bear in mind that she pled not guilty by reason of insanity at her arraignment hearing.’
    • ‘The entire day was beginning to look less and less like a bout of temporary insanity on my part.’
    • ‘In practice, the effect of this strict approach has not been greatly to swell the numbers of people pleading insanity.’
    • ‘A person doesn't pass into insanity when their situations are good.’
    • ‘Her lawyer tried to plead not guilty by reason of insanity, but that was rejected.’
    • ‘There's something about this place that breeds great madness and insanity.’
    • ‘He was sentenced to a minimum of 30 years in prison but was later transferred to Broadmoor on the grounds of insanity.’
    • ‘That tale about the true insanity and lies within a mental institution made a lot of sense to a lot of people.’
    mental illness, mental disorder, mental derangement, madness, insaneness, dementia, dementedness, lunacy, instability, unsoundness of mind, loss of reason
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    1. 1.1 Extreme foolishness or irrationality.
      ‘it might be pure insanity to take this loan’
      ‘the insanities of our time’
      • ‘If watching this FX series takes a strong stomach, observing Dr Sean McNamara and Dr Christian Troy (Julian McMahon) withstand the various insanities life slings their way can be a test of will and loyalty.’
      • ‘Yet, one has to wonder how National, despite the multitude of Labour insanities, only leads by one point.’
      • ‘I'd like to sleep for six months and ignore this pure insanity that we all call winter.’
      • ‘The way things are set up, the only people to benefit from this insanity are the organic farmers.’
      • ‘It revels in, even celebrates, the diverse insanities of American life.’
      • ‘If you can be sturdily present to yourself with all the internal garbage that comes up in sitting practice, then you can be present to the facts of deforestation and species extinctions, and all the insanities happening to our world today.’
      • ‘But the show does capture the various insanities and absurdities of his life, and is filled with clips of his more outrageous outfits.’
      • ‘The church was cold that day; most probably because the heating had broken down, but the insanities of the Church were not to be pondered on.’
      • ‘This still doesn't do justice to the sheer insanity of the whole enterprise though.’
      • ‘It was pure insanity that in such a short time we had gained such powerful interest.’
      • ‘I had progressed along some appropriate path, survived all the general miseries, horrors and institutional insanities that humans are fond of ordering themselves through.’
      • ‘You will if you see this one man show that tries to make sense of the insanity and absurdity of Israeli life by making us laugh.’
      • ‘Granting this patent was a demonstration of pure insanity in full force.’
      • ‘The unions and other farming bodies have been attempting to head off this insanity for the past two years - all to no avail.’
      • ‘Sarcasm raises its ugly head between all your sacred rites and ceremonies, but you cling on to your methodical insanities.’
      folly, foolishness, foolhardiness, idiocy, stupidity, imbecility, asininity, lunacy, madness, silliness, senselessness, brainlessness, thoughtlessness, irrationality, illogicality, absurdity, ludicrousness, ridiculousness
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Late 16th century: from Latin insanitas, from insanus (see insane).