darken

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To make dark or darker.
2. v. To give a darker hue to.
3. v. To fill with sadness; make gloomy.
4. v. To render vague or uncertain; obscure: The sudden drop in stock prices darkened the future for investors.
5. v. To tarnish or stain: a scandal that darkened the family's good name.
6. v. To become dark or darker.

Century Dictionary and Cyclopedia

1. To grow dark or darker.
2. To grow less white or clear; assume a darker hue or appearance: as, white paper darkens with age.
3. To deprive of light; make dark or darker: as, to darken a room by closing the shutters.
4. To obscure or shut out the light of.
5. To render less white or clear; impart a darker hue to: as, exposure to the sun darkens the complexion.
6. To obscure or cloud the meaning or intelligence of; perplex; render vague or uncertain.
7. To render gloomy; sadden.
8. To deprive of vision; strike with blindness.
9. Hence To deprive of intellectual or spiritual light; sink in darkness or ignorance.
10. To sully; make foul; make less bright or lustrous.
11. To hide; conceal.

Wiktionary

1. v. transitive To make dark or darker by reducing light.
2. v. intransitive To become dark or darker (having less light).
3. v. transitive To make dark or darker in colour.
4. v. intransitive To become dark or darker in colour.
5. v. transitive To render gloomy, dark(er) of mood
6. v. intransitive To become gloomy, dark of mood
7. v. transitive To blind, impair eyesight
8. v. intransitive To be blinded, loose clear vision

GNU Webster's 1913

1. v. To make dark or black; to deprive of light; to obscure.
2. v. To render dim; to deprive of vision.
3. v. To cloud, obscure, or perplex; to render less clear or intelligible.
4. v. To cast a gloom upon.
5. v. To make foul; to sully; to tarnish.
6. v. To grow or darker.

WordNet 3.0

1. v. become dark or darker
2. v. make dark or darker
3. v. tarnish or stain