• (n.) A salt of thiosulphuric acid; -- formerly called hyposulphite.
Thi`o·sul'phate noun (Chemistry) A salt of thiosulphuric acid; -- formerly called hyposulphite . » The sodium salt called in photography by the name sodium hyposulphite , being used as a solvent for the excess of unchanged silver chloride, bromide, and iodide on the sensitive...
thiosulphate (British)