pie in the sky

1. 不可及的梦想；渺茫的希望；不能保证实现的诺言
   Political promises are often pie in the sky.

   政治诺言常常是不能够保证实现的。

   What you said is only pie in the sky.

   你所说的实在是渺茫得很。

• (as) —— as pie
  informal very ——.
• pie in the sky
  informal something pleasant to contemplate but very unlikely to be realized.