%hydrocyanic%

a. [ Hydro-, 2 + anic: cf. F. hydrocyanique. ] (Chem.) Pertaining to, or derived from the combination of, hydrogen and cyanogen. [ 1913 Webster ]

Hydrocyanic acid (Chem.), a colorless, mobile, volatile liquid, HCN, having a characteristic peach-blossom odor. It is one of the most deadly poisons. It is made by the action of sulphuric acid on yellow prussiate of potassium (potassium ferrocyanide), and chemically resembles hydrochloric and hydrobromic acids. Called also prussic acid, hydrogen cyanide, etc. [ 1913 Webster ]