/ Dictionary / Index P pyrophosphate: Meaning and Definition of Find definitions for: py•ro•phos•phate Pronunciation: (pī"ru-fos'fāt), [key] — n. Chem. a salt or ester of pyrophosphoric acid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: pyrophosphate (Thesaurus) pyrophoric pyrophosphoric acid 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