/ Dictionary / Index P pyritohedron: Meaning and Definition of Find definitions for: py•ri•to•he•dron Pronunciation: (pī-rī"tu-hē'drun, pu-, pī"rī-), [key] — n. Crystall. a crystal form of 12 pentagonal faces. Also calledSee diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrites pyro 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