5 letters · 19 points in Scrabble
noun someone deranged and possibly dangerous
adjective affected with madness or insanity
adjective foolish; totally unsound
originFrom craze (“to crush”) + -y, akin to being "crazed up". Compare cracked up (“suffered a mental breakdown; be insane”), crackpot. Compare typologically Russian чо́кнутый (čóknutyj).
Etymology from Wiktionary, CC BY-SA 3.0