Answer:

STYGIAN

Answer	Crossword Clue
STYGIAN	Hellish, in the Greek sense
STYGIAN	Dark and gloomy
STYGIAN	Like Charon's world

STYGIAN	Dark.
STYGIAN	Gloomy as the infernal river.
STYGIAN	Infernal.
STYGIAN	Gloomy
STYGIAN	Hellish
STYGIAN	Dark and forbidding

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.