be (as) nutty as a fruitcake
US /bi əz ˈnʌt.i əz ə ˈfruːt.keɪk/
UK /bi əz ˈnʌt.i əz ə ˈfruːt.keɪk/

1.
疯疯癫癫的, 古怪的
to be crazy or eccentric
:
•
My aunt is as nutty as a fruitcake, but we love her.
我姑姑疯疯癫癫的,但我们爱她。
•
You'd have to be as nutty as a fruitcake to believe that story.
你肯定疯了才会相信那个故事。