Phlegethon
/ˈflɛɡɪθɒn/ /ˈflɛdʒɪθɒn/Chiefly poetic
noun
Something regarded as resembling the mythical river Phlegethon; a river of fire, a seething torrent or turmoil.
Origin
Early 19th century; earliest use found in Lord Byron (1788–1824), poet. From Phlegethon (classical Latin Phlegethont-, Phlegethōn, ancient Greek Φλεγέθοντ-, Φλεγέθων, lit. ‘burning, blazing’), the name of a mythological river of fire, one of the five rivers of Hades.