Source : Webster's Revised Unabridged Dictionary (1913)

Hydrosulphide \Hy`dro*sul"phide\, n. (Chem.)
   One of a series of compounds, derived from hydrogen sulphide
   by the replacement of half its hydrogen by a base or basic
   radical; as, potassium hydrosulphide, {KSH}. The
   hydrosulphides are analogous to the hydrates and include the
   mercaptans.