INSANE

adj. 1 mad, demented, psychotic, schizophrenic, schizoid, non compos mentis, manic, maniacal, lunatic, deranged, unbalanced, psychoneurotic, neurotic, eccentric, crazy, of unsound mind, crazed, unhinged, out of one's mind or head, mad as a hatter or a March hare, quirky, Colloq round the bend or twist, off one's rocker or chump, loopy, loony, certifiable, mental, screwy, dotty, cuckoo, not all there, not have all one's marbles, off-the-wall, out of it, Brit potty, Slang daft, nutty (as a fruit cake), nuts, spaced out, spacy, batty, have bats in one's belfry, not right upstairs, barmy (in the crumpet), crackers, have a screw loose, schizo, Brit bonkers, US bugs, bughouse, loco, crazy as a bedbug, (gone) off the deep end, kooky, kinky, out to lunch Witney was certified insane and institutionalized You're insane if you think I am going out on that ledge. 2 stupid, dumb, dull, silly, asinine, ridiculous, idiotic, irrational, absurd, fatuous, ludicrous, foolish, nonsensical, irresponsible, reckless, wild, imbecilic, moronic, feeble-minded, hare-brained, addle-pated, addle-brained, scatterbrained, thimble-witted, attocerebral, Brit gormless, Colloq nutty, screwy, crazy People in love sometimes do insane things