insane

1. Afflicted with or characteristic of mental derangement (synset 302081496)
   "was declared insane"; "insane laughter"
   also:

   • irrational - not consistent with or using reason
   • unreasonable - not reasonable; not showing good judgment
   similar to:

   • around the bend, balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kookie, kooky, loco, loony, loopy, nuts, nutty, round the bend, wacky, whacky - informal or slang terms for mentally irregular
   • brainsick, crazy, demented, disturbed, mad, sick, unbalanced, unhinged - affected with madness or insanity
   • certifiable, certified - fit to be certified as insane (and treated accordingly)
   • crackbrained, idiotic - insanely irresponsible
   • crazed, deranged, half-crazed - driven insane
   • fey, touched - slightly insane
   • hebephrenic - suffering from a form of schizophrenia characterized by foolish mannerisms and senseless laughter along with delusions and regressive behavior
   • lunatic, moonstruck - insane and believed to be affected by the phases of the moon
   • maniac, maniacal - wildly disordered
   • manic-depressive - suffering from a disorder characterized by alternating mania and depression
   • maniclike - resembling the mania of manic-depressive illness
   • mentally ill, unsound, unstable - suffering from severe mental illness
   • non compos mentis, of unsound mind - not of sound mind, memory, or understanding; in law, not competent to go to trial
   • paranoid - suffering from paranoia
   • psychopathic, psychopathologic, psychopathological - suffering from an undiagnosed mental disorder
   • psychotic - characteristic of or suffering from psychosis
   • raving mad, wild - talking or behaving irrationally
   • schizophrenic - suffering from some form of schizophrenia
   • screw-loose, screwy - not behaving normally
2. Very foolish (synset 302582476)
   "harebrained ideas"; "took insane risks behind the wheel"; "a completely mad scheme to build a bridge between two mountains"
   similar to: foolish - devoid of good sense or judgment
   same as: harebrained, mad

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