Someone deranged and possibly dangerous.

synonyms: crazy, looney, nutcase, weirdo.

Dutch: oelewapper, koekert
Polish: obłąkaniec, chory na głowę, pomyleniec, pomylony, nienormalny, szaleniec, wariat

Informal or slang terms for mentally irregular.

synonyms: around the bend, balmy, barmy, bats, batty, bonkers, buggy, cracked, crackers, daft, dotty, fruity, haywire, kookie, kooky, loco, loopy, nuts, nutty, round the bend, wacky, whacky ... show more.

Roget 503: insane, mad, lunatic, loony [Coll.]; crazy, crazed, aliene^†, non compos mentis; not right, cracked, touched; bereft of reason; all possessed, unhinged, unsettled in one's mind; insensate, reasonless, beside oneself, demented, daft; phrenzied^†, frenzied, frenetic; possessed, possessed with a devil; deranged, maddened, moonstruck; shatterpated^†; mad-brained, scatter brained, shatter brained, crackbrained; touched, tetched [Coll.]; off one's head.    [behavior suggesting insanity] maniacal; delirious, lightheaded, incoherent, rambling, doting, wandering; frantic, raving, stark staring mad, stark raving mad, wild-eyed, berserk; delusional, hallucinatory.    [behavior somewhat resembling insanity] corybantic^†, dithyrambic; rabid, giddy, vertiginous, wild; haggard, mazed; flighty; distracted, distraught; depressed; agitated, hyped up; bewildered etc. (uncertain) 475.    mad as a March hare, mad as a hatter; of unsound mind etc. n.; touched in one's head, wrong in one's head, not right in one's head, not in one's right mind, not right in one's wits, upper story; out of one's mind, out of one's wits, out of one's skull [Coll.], far gone, out of one's senses, out of one's wits; not in one's right mind.    fanatical, infatuated, odd, eccentric; hypped^†, hyppish^†; spaced out [Coll.].    imbecile, silly, etc. 499.    ... show more

Polish: odjechany