insanity

/ɪnˈsænədi/

/ɪnˈsænɪti/

Other forms: insanities

Insanity is an ongoing state of extreme mental illness, which may cause abnormal or antisocial behaviors. If you bark at cats and meow at dogs, you might suffer from insanity.

The noun insanity originates from the Latin word insanitatem, meaning "unhealthfulness" relating to the mind. It is believed that master artist Vincent van Gogh, who cut off his ear and gave it to a prostitute, experienced periods of insanity. But this term can also refer to things people perceive as unconventional or foolish, like your neighbor who quit his job, sold all his belongings, and bought a boat to sail around the world.

Definitions of insanity

1. noun

   relatively permanent disorder of the mind
   antonyms:

   sanity

   normal or sound powers of mind

   types:

   insaneness, lunacy, madness

   obsolete terms for legal insanity

   dementedness, dementia

   mental deterioration of organic or functional origin

   irrationality, unreason

   the state of being irrational; lacking powers of understanding

   derangement, mental unsoundness, unbalance

   a state of mental disturbance and disorientation

   craziness, daftness, flakiness

   informal terms for insanity

   Korsakoff's psychosis, Korsakoff's syndrome, Korsakov's psychosis, Korsakov's syndrome, alcohol amnestic disorder, alcoholic dementia, polyneuritic psychosis

   dementia observed during the last stages of severe chronic alcoholism; involves loss of memory for recent events although long term memory is intact

   presenile dementia

   dementia with onset before the age of 65

   senile dementia, senile psychosis

   dementia of the aged; results from degeneration of the brain in the absence of cerebrovascular disease

   type of:

   mental disease, mental illness, psychopathy

   any disease of the mind; the psychological state of someone who has emotional or behavioral problems serious enough to require psychiatric intervention