n. [ L., fr. Gr. &unr_;. ] (Myth.) A river in the Nether World or infernal regions; also, the infernal regions themselves. By some of the English poets it was supposed to be a flaming lake or gulf. Shak. [ 1913 Webster ]
n.
a. Of or pertaining to Acheron; infernal; hence, dismal, gloomy; moribund. [ 1913 Webster ]