| Acherontic | a. Of or pertaining to Acheron; infernal; hence, dismal, gloomy; moribund. [ 1913 Webster ] |
| acheronian | (adj) dark and dismal as of the rivers Acheron and Styx in Hades; ; -Wordsworth, Syn. Acherontic, Stygian, Example: in the depths of an Acheronian forest; upon those roseate lips a Stygian hue |