Synonyms of insane

1. insane (vs. sane), amuck, amok, berserk, demoniac, demoniacal, possessed(predicate), balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kooky, kookie, loco, loony, loopy, nuts, nutty, round the bend, around the bend, wacky, whacky, brainsick, crazy, demented, disturbed, mad, sick, unbalanced, unhinged, certifiable, certified, crackbrained, idiotic, crazed, deranged, half-crazed, fey, touched(predicate), hebephrenic, lunatic, moonstruck, maniacal, maniac(predicate), manic-depressive, maniclike, mentally ill, unsound, unstable, non compos mentis(predicate), of unsound mind(predicate), paranoid, psychopathic, psychopathologic, psychopathological, psychotic, raving mad, wild, schizophrenic, screw-loose, screwy, irrational, unreasonable: usage: afflicted with or characteristic of mental derangement; "was declared insane"; "insane laughter"
2. harebrained, insane, mad, foolish (vs. wise): usage: very foolish; "harebrained ideas"; "took insane risks behind the wheel"; "a completely mad scheme to build a bridge between two mountains"