/ Dictionary / Index P pyrite: Meaning and Definition of Find definitions for: py•rite Pronunciation: (pī'rīt), [key] — n. a very common brass-yellow mineral, iron disulfide, FeS, with a metallic luster, burned to sulfur dioxide in the manufacture of sulfuric acid: chemically similar to marcasite, but crystallizing in the isometric system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pyrite (Thesaurus) Pyriphlegethon pyrites 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