/ Dictionary / Index P pyin: Meaning and Definition of Find definitions for: py•in Pronunciation: (pī'in), [key] — n. Biochem. an albuminous constituent of pus. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pygostyle pyjamas Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language