The Collaborative International Dictionary
Hypophosphorous
Hypophosphorous \Hy`po*phos"phor*ous\, a. [Pref. hypo- + phosphorous.] (Chem.) Pertaining to, or containing, phosphorus in a lower state of oxidation than in phosphoric compounds; as, hypophosphorous acid.
Hypophosphorous acid (Chem.), an acid, H3PO2, whose salts are produced by the action of barium hygrate on phosphorus. It may be obtained from its water solution, by exaporation and freezing, as a white crystalline substance. It is a powerful reducing agent.
Wiktionary
hypophosphorous
a. (context chemistry English) Of or pertaining to hypophosphorous acid or its derivatives