/ Dictionary / Index P Pyridium: Meaning and Definition of Find definitions for: Py•rid•i•um Pronunciation: (pī-rid'ē-um, pi-), [key] — Pharm., Trademark. Pharm.,Trademark. a brand of phenazopyridine. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pyridium (Thesaurus) pyridine pyridostigmine bromide Related Content Daily Word Quiz: simian Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language