insanity
//ɪnˈsænɪti//
Noun
1
The state of being seriously mentally ill; madness.
The court ruled that he was not guilty by reason of insanity.
2
Extreme foolishness or irrationality in behavior or thought.
It would be insanity to quit your job without having another one lined up.
3
(Law) A mental condition that renders a person incapable of being held legally responsible for their actions.
The defendant was found not guilty by reason of insanity.