Synonyms of the word

darkening

• v. present participle of darken.
• n. The act of something becoming darker.

blackening

• v. present participle of blacken.
• n. The act of turning black in colour; a black stain or mark.

dark

• adj. Having an absolute or (more often) relative lack of light.
• adj. (of colour) Dull or deeper in hue; not bright or light.
• adj. Hidden, secret, obscure.
• adj. Without moral or spiritual light; sinister, malign.
• adj. Conducive to hopelessness; depressing or bleak.
• adj. Lacking progress in science or the arts; said of a time period.
• adj. With emphasis placed on the unpleasant aspects of life; said of a work of fiction, a work of nonfiction…
• n. A complete or (more often) partial absence of light.
• n. (uncountable) Ignorance.
• n. (uncountable) Nightfall.
• n. A dark shade or dark passage in a painting, engraving, etc.

gloomy

• adj. Imperfectly illuminated; dismal through obscurity or darkness; dusky; dim; clouded.
• adj. Affected with, or expressing, gloom; melancholy; dejected.

grim

• adj. dismal and gloomy, cold and forbidding.
• adj. rigid and unrelenting.
• adj. ghastly or sinister.
• adj. (Britain, slang) disgusting; gross.

hopeless

• adj. Without hope; despairing; not expecting anything positive.
• adj. Giving no ground of hope; promising nothing desirable; desperate.
• adj. Without talent, not skilled.