from
The Collaborative International Dictionary of English v.0.48
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.
[1913 Webster]
{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.
[1913 Webster]