From Longman Dictionary of Contemporary Englishbe out of your mindbe out of your mindinformal to be stupid or crazy He must have been out of his mind to employ her. → mind
Examples from the Corpus
be out of your mind• Are you out of your mind?• Coronado, who thought him to be out of his mind, reluctantly saw the men off.• You'd be out of your mind to sell it now.• The fans were out of their minds, and the din was deafening.• In fact, I am out of my mind, because she's in it!• He said I was out of my mind.• You must be out of your mind. 