Hy`po*sul"phur*ous (?), a. [Pref. hypo- + sulphurous.] Chem.
Pertaining to, or containing, sulphur, all, or a part, in a low state of oxidation.
Hyposulphurous acid. (a) Thiosulphuric acid. [Obs.] (b) An acid, H2SO2, obtained by the reduction of sulphurous acid. It is not obtained in the free state, but in an orange-yellow water solution, which is a strong reducing and bleaching agent. Called also hydrosulphurous acid.
© Webster 1913.