Webster's Revised Unabridged Dictionary · 1913

metaphosphoric

metaphosphoric , adjective

[Prefix meta- + phosphoric.]

(Chemistry) Pertaining to, or designating, a monobasic acid, HPO3, analogous to nitric acid, and, by heating phosphoric acid, obtained as a crystalline substance, commonly called glacial phosphoric acid. Compare the tribasic orthophosphoric acid.