cyanogen

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A colorless, flammable, pungent, highly poisonous gas, C₂N₂, used as a rocket propellant, an insecticide, and a chemical weapon.
2. n. A univalent radical, CN, found in simple and complex cyanide compounds.

Century Dictionary and Cyclopedia

1. n. Chemical symbol Cy. A compound radical, CN, composed of one atom of nitrogen and one of carbon. This radical cannot exist free, but the double radical (C₂N₂) exists as a gas called dicyanogen. It is a gas of a strong and peculiar odor, resembling that of crushed peach-leaves, and burning with a rich purple flame. Under a pressure of between three and four atmospheres it becomes a limpid liquid; and it is highly poisonous and irrespirable. It is obtained by heating dry mercury cyanide. It unites with oxygen, hydrogen, and most other non-metallic elements, and also with the metals, forming cyanides. In combination with iron it forms pigments of a dark-blue color, variously called Prussian blue, Chinese blue, Berlin blue, and Turnbull's blue. Also cyan.

Wiktionary

1. n. A colourless, poisonous gas used as a rocket propellant, an insecticide and in chemical warfare.
2. n. chemistry The pseudohalogen (CN)2.
3. n. chemistry The radical -CN.

GNU Webster's 1913

1. n. (Chem.) A colorless, inflammable, poisonous gas, C2N2, with a peach-blossom odor, so called from its tendency to form blue compounds; obtained by heating ammonium oxalate, mercuric cyanide, etc. It is obtained in combination, forming an alkaline cyanide when nitrogen or a nitrogenous compound is strongly ignited with carbon and soda or potash. It conducts itself like a member of the halogen group of elements, and shows a tendency to form complex compounds. The name is also applied to the univalent radical, CN (the half molecule of cyanogen proper), which was one of the first compound radicals recognized.

WordNet 3.0

1. n. a colorless toxic gas with a pungent almond odor; has been used in chemical warfare