any sodium salt of any phosphoric acid, esp one of three salts of orthophosphoric acid having formulas NaH2PO4 (monosodium dihydrogen orthophosphate), Na2HPO4 (disodium monohydrogen orthophosphate), and Na3PO4 (trisodium orthophosphate)
sodium phosphate in American English
any of various clear, crystalline sodium salts of phosphoric acid, widely used in industry