HSCN

from The Collaborative International Dictionary of English v.0.48

Sulphocyanic \Sul`pho*cy*an"ic\, a. [See {Sulphur}, {Cyanic}.]
   (Chem.)
   Of, pertaining to, derived from, or designating, a sulphacid,
   {HSCN}, analogous to cyanic acid, and obtained as a colorless
   deliquescent crystalline substance, having a bitter saline
   taste, and not poisonous.
   [1913 Webster]