Phlĕgĕthon, ontis, m., = Φλεγέθων (burning, blazing),
I a river in the Lower World , which ran with fire instead of water : Chaos et Phlegethon loca nocte silentia late, Verg. A. 6, 265: Tartareus, id. ib. 6, 551; Stat. Th. 4, 522: ardenti freto Phlegethon harenas igneus tostas agens, Sen. Thyest. 1018; id. Oedip. 162; id. Agam. 752. —Hence,
A Phlĕgĕthontēus , a, um, adj., Phlegethontian : ripa, Claud. Rapt. Pros. 1, 88.—
B Phlĕgĕthontis , ĭdis, f. adj., Phlegethontian : unda, Ov. M. 15, 532: lympha, id. ib. 5, 544.