\Sul*phy"drate\, n. (Chem.)
A compound, analogous to a hydrate, regarded as a salt of
sulphydric acid, or as a derivative of hydrogen sulphide in
which one half of the hydrogen is replaced by a base (as
potassium sulphydrate, {KSH}), or as a hydrate in which the
oxygen has been wholly or partially replaced by sulphur.