'Acherontic' definitions:

Definition of 'Acherontic'

(from WordNet)
adjective
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 [syn: Acheronian, Acherontic, Stygian]