Definition of insane adjective from the Oxford Advanced Learner's Dictionary



    BrE BrE//ɪnˈseɪn//
    ; NAmE NAmE//ɪnˈseɪn//
    Describing strange traits
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  1. 1seriously mentally ill and unable to live in normal society Doctors certified him as insane. The prisoners were slowly going insane. opposite sane Synonymsmentally illinsane neurotic psychotic disturbed unstableThese words all describe somebody who is suffering from a mental illness.mentally ill suffering from an illness of the mind, especially in a way that affects the way you think and behaveinsane [not usually before noun] (rather formal) suffering from a serious mental illness and unable to live in normal society:The question is, was the man insane when he committed the crime? In informal English insane can describe somebody who is not suffering from a mental illness, but whose mind does not work normally, especially because they are under pressure. This meaning is used especially in the phrases go insane and drive somebody insane.neurotic (medical) suffering from or connected with neurosis (= a mental illness in which a person suffers strong feelings of fear and worry) :the treatment of anxiety in neurotic patients In informal English neurotic is also used to describe somebody who is not suffering from a mental illness, but is not behaving in a calm way because they are worried about something:She became neurotic about keeping the house clean.psychotic (medical) suffering from or connected with psychosis (= a serious mental illness in which thought and emotions lose connection with external reality). In informal English psychotic is sometimes used to describe anyone suffering from a mental illness, but in correct medical usage it only describes people who have difficulty relating to external reality. It contrasts with neurotic, which describes people who are less seriously mentally ill and are still able to distinguish what is real from what is not.disturbed mentally ill, especially because of very unhappy or shocking experiences:He works with emotionally disturbed children.unstable having emotions and behaviour that are likely to change suddenly and unexpectedlyPatterns neurotic/​psychotic/​disturbed/​unstable behaviour neurotic/​psychotic illnesses/​disorders/​symptoms/​patients seriously mentally ill/​neurotic/​psychotic/​disturbed emotionally/​mentally disturbed/​unstable See related entries: Describing strange traits
  2. 2the insane noun [plural] people who are insane a hospital for the insane More Like This Plural adjectival nouns the blind, the deaf, the destitute, the dead, the dying, the elderly, the faithful, the homeless, the injured, the insane, the jobless, the middle aged, the old, the poor, the rich, the sick, the squeamish, the wealthy, the wicked, the wounded, the youngSee worksheet.
  3. 3(informal) very stupid, crazy or dangerous I must have been insane to agree to the idea. This job is driving me insane (= making me feel very angry). see also insanity
  4. Word Originmid 16th cent.: from Latin insanus, from in- ‘not’ + sanus ‘healthy’.Extra examples He is criminally insane, unable to stop himself attacking women. He later became insane and was confined to an asylum. He was clearly insane. He went almost insane when he heard that his daughter had died. In 1975 she was certified clinically insane and sent to a mental hospital. It seems insane to cut the budget now. She claimed she was temporarily insane during the attack. The whole idea is quite insane. You’re driving me nearly insane with that noise. Doctors certified her as insane. It was an insane risk to take. She was driving me insane with her constant chatter. The question is, was the man insane when he committed the crime?
See the Oxford Advanced American Dictionary entry: insane