基本解释n.精神失常；精神病；愚行同根派生 英汉例句用作名词 (n.)It's sheer lunacy driving in this weather.天气这麽坏还开车，简直是疯了。Bridge designers had anticipated such lunacy and invented the crossing guard.吊桥的设计者早就预料到会有这样的精神病穿越吊桥，因而设计了防护装置。