Definition of "insane" in English

adjective

1. Exhibiting unsoundness or disorder of mind; not sane; utterly mad.

2. Used by or relating to insane people.

   • an insane hospital
   • an insane asylum

3. Causing insanity or madness.

4. (informal) Characterized by excess or the utmost folly; ridiculous; impractical.

   • an insane plan
   • an insane amount of money

5. (slang) Extremely good; incredibly amazing.

   • That guy is insane at FPS games.

6. (informal) Enraged; furious.