/ Dictionary / Index P pyosis: Meaning and Definition of Find definitions for: py•o•sis Pronunciation: (pī-ō'sis), [key] — n. Pathol. the formation of pus; suppuration. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyorrhea pyothorax Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language