n.

1. 硬紙板，卡紙板[U]
   The box is made of cardboard.

   這箱子是硬板紙製的。

a.

1. 硬紙板製的；扁而硬的
   He put his books in a large cardboard box.

   他將書放入一個大硬板紙箱內。

2. 不真實的，不自然的；虛構的，沒有深度的，膚淺的
   The story has several cardboard characters.

   這個故事裡有好幾個虛構的人物。

n.

1. pasteboard or stiff paper.
2. [as modifier] (of a fictional character) lacking depth and realism:
   superficial, cardboard characters.