/ Dictionary / Index P pyrophotometer: Meaning and Definition of Find definitions for: py•ro•pho•tom•e•ter Pronunciation: (pī"rō-fō-tom'i-tur), [key] — n. Physics. a form of pyrometer that measures temperature by optical or photometric means. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pyrophosphoric acid pyrophyllite Related Content Daily Word Quiz: cygnet Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language