a.

1. 愚蠢的，笨的
   It is stupid to do such a thing.

   做这种事真蠢。

2. 麻木的，无知觉的；迟钝的
   The sailor was stupid with liquor.

   那水手醉得不省人事。

3. 无聊的，乏味的，讨厌的[B]
   It was a stupid book.

   那是一本无聊的书。

n.

1. 笨蛋，傻瓜[C]

adj.

1. lacking intelligence or common sense.
   ▸informal used to express exasperation or boredom:

   stop messing about with your stupid paintings!
2. dazed and unable to think clearly.