in‧sane / ɪnˈseɪn / adjective
1 informal completely stupid or crazy, often in a way that is dangerous :
That’s an insane risk.
The whole idea sounds absolutely insane to me.
Why did you do that? Have you gone insane ?
2 someone who is insane is permanently and seriously mentally ill so that they cannot live in normal society :
The killer was declared criminally insane.
3 the insane people who are mentally ill :
a hospital for the insane
4 drive somebody insane informal to make someone feel more and more annoyed or angry, usually over a long period of time SYN drive somebody mad :
My little brother’s been driving me insane all weekend.
— insanely adverb :
insanely jealous
She giggled insanely.