/ Dictionary / Index M metaphosphoric acid: Meaning and Definition of Find definitions for: met'a•phos•phor'ic ac'id Pronunciation: (met"u-fos-fôr'ik, -for'-), [key] — Chem. Chem. an acid, HPO, derived from phosphorous pentoxide, and containing the smallest amount of water of the phosphoric acids. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. metaphosphate metaphrase Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language