Meaning of INSANITY in English
/ ɪnˈsænəti; NAmE / noun [ U ]
the state of being insane
SYN madness :
He was found not guilty, by reason of insanity.
actions that are very stupid and possibly dangerous
SYN madness , lunacy :
It would be sheer insanity to attempt the trip in such bad weather.
late 16th cent.: from Latin insanitas , from insanus , from in- not + sanus healthy.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005