vi.

1. （月）亏，缺
   Don't be sad. The moon will become full after it wanes.

   不要伤感。月缺以后会有满月。

2. 变暗淡；变小；减少
   My interest in the problem waned.

   我对那个问题的兴趣减弱了。

3. 衰落；没落；消逝
   When did the empire begin to wane?

   那个帝国何时开始衰落的？

4. 退潮

n.[U]

1. 月亏；月亏期
   The moon is on the wane.

   月亮渐亏。

2. 衰退；衰退期
   His fortune is on the wane.

   他命运不济了。

v.

1. (of the moon) have a progressively smaller part of its visible surface illuminated, so that it seems to decrease in size.
2. become weaker.

n.