/ Dictionary / Index P Pyriphlegethon: Meaning and Definition of Find definitions for: Pyr•i•phleg•e•thon Pronunciation: (pir"u-fleg'u-thon", -flej'-), [key] — n. Class. Myth. Phlegethon (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrimidine pyrite Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language