nutty as a fruitcake

1. Crazy, idiotic, as in Mary's nutty as a fruitcake if she thinks she can get away with that. The adjective nutty meaning “insane” was first recorded in 1821; the similarity to fruitcake, which literally contains nuts as well as fruit, was first recorded in 1935.

Related Words

• deranged 
• hysterical 
• mad 
• maniacal 
• manic 
• psychotic 
• unhinged