Main Entry: sty·gian

Pronunciation: \ˈsti-j(ē-)ən\

Function: adjective

Usage: often capitalized

Etymology: Latin stygius, from Greek stygios, from Styg-, Styx Styx

Date: 1513

1 : of or relating to the river Styx
2 : extremely dark, gloomy, or forbidding <the stygian blackness of the cave>