Synonyms: Acheronian, Acherontic, Stygian
Definition: dark and dismal as of the rivers Acheron and Styx in Hades
Usage: in the depths of an Acheronian forest; upon those roseate lips a Stygian hue-Wordsworth
Similar words: dark
Definition: devoid of or deficient in light or brightness; shadowed or black
Usage: sitting in a dark corner; a dark day; dark shadows; dark as the inside of a black cat
Synonyms: Stygian
Definition: hellish
Usage: Hence loathed Melancholy.../In Stygian cave forlorn- Milton