darken /ˈdɑːkən/ TEM4 ( darkening, darkened, darkens )

• 1. 

  V-T/V-I If something darkens or if a person or thing darkens it, it becomes darker. 变暗; 使变暗

  例：

  The sky darkened abruptly.

  天突然变暗了。

• 2. 

  V-T/V-I If someone's mood darkens or if something darkens their mood, they suddenly become unhappy. 黯淡; 使黯淡 [文学性]

  例：

  My sunny mood suddenly darkened.

  我快乐的情绪突然黯淡下来。