Monoxide (noun)

1. A compound containing only one oxygen atom in its molecule.
2. A chemical compound that contains one oxygen atom and one other element. The chemical formula is MO. It is typically a colorless, odorless, and toxic gas.

Origin:

From the greek monos ("single") + oxys ("acid, sour") + -ide.

Examples:

1. Carbon monoxide is a toxic gas that can be fatal if inhaled in large amounts.
2. Monoxide of nitrogen is a major contributor to air pollution in urban areas.
3. Iron monoxide is a dark-red powder that is used in the production of pigments.
4. The fire department determined that the cause of the explosion was a build-up of monoxide gas in the basement.
5. The plant releases large amounts of sulfur monoxide into the atmosphere.