Meaning of orthophosphoric acid

or'tho•phos•phor'ic ac'id

Pronunciation: (ôr'thō-fos-fôr'ik, -for'-, ôr"-), [key]
— Chem. Chem.
  1. a colorless, crystalline solid, HPO, the tribasic acid of pentavalent phosphorus: used chiefly in fertilizers, as a source of phosphorus salts, and in soft drinks as an acidulant and flavoring agent.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.