acheronian
/ˌækəˈroʊniən/
adjective
- Relating to or resembling the underworld or hell; dark, gloomy, or dismal.
- The abandoned factory had an acheronian atmosphere that made visitors shiver.
- In the poem, the hero crosses an acheronian river to reach the land of the dead.
- The storm clouds created an acheronian gloom over the entire valley.