insanity

[in-san-i-tee] /ɪnˈsæn ɪ ti/
noun, plural insanities.
1.
the condition of being insane; a derangement of the mind.
Synonyms: dementia, lunacy, madness, craziness, mania, aberration.
2.
Law. such unsoundness of mind as frees one from legal responsibility, as for committing a crime, or as signals one's lack of legal capacity, as for entering into a contractual agreement.
3.
Psychiatry. (formerly) psychosis.
4.
  1. extreme foolishness; folly; senselessness; foolhardiness:
    Trying to drive through that traffic would be pure insanity.
  2. a foolish or senseless action, policy, statement, etc.:
    We've heard decades of insanities in our political discourse.
Origin
1580-90; < Latin insānitās. See in-3, sanity
Examples from the web for insanity
  • Next to insanity itself, the saddest thing in the world is the way in which the public regard it.
  • They say that the definition of insanity is continuing to do the same thing but expecting to get different results.
  • Fortunately, the government has understood the insanity of this.
  • History won't be kind to this insanity of climate blame.
  • They can't listen, can't comprehend their own insanity.
  • No question would seem harder to settle than the sanity or insanity of our fellows.
  • Now a new chance to halt this insanity has emerged in the unlikely form of climate-change negotiations.
  • These were the two things that were driving me slowly down the road to insanity.
  • The insanity defense, rarely used, is widely misunderstood.
  • The official belief is that there is little or no prison-made insanity.
British Dictionary definitions for insanity

insanity

/ɪnˈsænɪtɪ/
noun (pl) -ties
1.
relatively permanent disorder of the mind; state or condition of being insane
2.
(law) a defect of reason as a result of mental illness, such that a defendant does not know what he or she is doing or that it is wrong
3.
utter folly; stupidity
Word Origin and History for insanity
n.

1580s, "state of being insane," from Latin insanitatem (nominative insanitas) "unhealthfulness," noun of quality from insanus (see insane). Meaning "extreme folly" is from 1844.

insanity in Medicine

insanity in·san·i·ty (ĭn-sān'ĭ-tē)
n.

  1. Persistent mental disorder or derangement.

  2. Unsoundness of mind sufficient in the judgment of a civil court to render a person unfit to maintain a contractual or other legal relationship or to warrant commitment to a mental health facility.

  3. In most criminal jurisdictions, a degree of mental malfunctioning considered to be sufficient to relieve the accused of legal responsibility for the act committed.