/nuts/ , Slang.
interj.
1. Also, nerts, nertz . (used to express disgust, defiance, disapproval, despair).
adj.
2. insane; crazy.
3. be nuts about ,
a. to be extremely or excessively enthusiastic about; be fervent in one's admiration of: Both of them are nuts about chamber music.
b. to be deeply in love with: He's nuts about his new girlfriend.
[ 1900-05; pl. of NUT ]