/ Dictionary / Index P porphyroid: Meaning and Definition of Find definitions for: por•phy•roid Pronunciation: (pôr'fu-roid"), [key] — n. a rock resembling porphyry. a sedimentary rock that has been metamorphosed so as to leave some original crystals in a fine-textured, layered matrix. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. porphyrize porphyry Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language