Cyanide (noun)

1. A chemical compound containing the cyanide ion, CN-.
2. A toxic chemical that can be fatal if ingested or inhaled.
3. A chemical compound containing the group -C≡N, used in certain types of chemical reactions and in the production of certain chemicals, plastics, and dyes.

Origin:

From french cyanure, from greek kyanos ("dark blue") + -ide.

Examples:

1. Cyanide is used in the extraction of gold and silver from ores.
2. Inhaling cyanide can cause rapid breathing, confusion and seizures.
3. The poison used to kill the pests was cyanide.
4. It is used in electroplating, metallurgy and photography.
5. The smoke from burning plastics can contain cyanide and other toxic gases.