River in Hades in Greek mythology, across which Charon ferried the souls of the dead (4)

I believe the answer is:

styx

(Other definitions for styx that I've seen before include "River crossed at death" , "The last river one crosses" , "Mythological river in Hades" , "Infernal runner" , "One of the underworld rivers" .)

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.