Insanity is the state of being insane.
a psychiatrist who specialized in diagnosing insanity.
一位专门诊断精神错乱的精神病学家。
If you describe a decision or an action as insanity, you think it is very foolish.
the final financial insanity of the 1980s.
20世纪80年代最后的金融疯狂。