† hypoˈsulphateChem.Obs. [f. hypo- 5 + sulphate.] A salt of hyposulphuric acid. (Now called a dithionate.) 1819J. G. Children Chem.Anal. 435 Hyposulphate of lime crystallizes in regular hexagonal plates.1868–72Watts Dict.Chem. V. 637 Dithionates or Hyposulphates.