/ Dictionary / Index P pyrites: Meaning and Definition of Find definitions for: py•ri•tes Pronunciation: (pī-rī'tēz, pu-, pī'rīts), [key] — pl. -tes. pyrite. marcasite. any of various other metallic sulfides, as of copper or tin. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pyrites (Thesaurus) pyrite pyritohedron Related Content Daily Word Quiz: miscreant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language