darken

Short definition from Wiktionary

Verb

1. 1
   To make dark or darker by reducing light.
2. 2
   To become dark or darker (having less light).
3. 3
   To get dark (referring to the sky, either in the evening or as a result of cloud).
4. 4
   To make dark or darker in colour.
5. 5
   To become dark or darker in colour.
6. 6
   To render gloomy, darker in mood.
7. 7
   To become gloomy, darker in mood.
8. 8
   To blind, impair the eyesight.
9. 9
   To be blinded, lose one’s eyesight.
10. 10
    To cloud, obscure, or perplex; to render less clear or intelligible.
11. 11
    To make foul; to sully; to tarnish.
12. 12
    To be extinguished or deprived of vitality, to die.