- Stygian - hellish; "Hence loathed Melancholy.../In Stygian cave forlorn"- Milton
Antonym: supernal (indirect, via infernal)
- Acheronian, Acherontic, Stygian - dark and dismal as of the rivers Acheron and Styx in Hades; "in the depths of an Acheronian forest"; "upon those roseate lips a Stygian hue"-Wordsworth
Antonym: light (indirect, via dark)