(chemistry) any oxide containing a single oxygen atom in each molecule or formula unit

plural of monoxide

(inorganic chemistry) A chemical compound with the formula SiO. In the atmosphere it oxidizes quickly into SiO₂, but has been detected in stellar objects and has been described as the most common oxide of silicon in the universe.

(inorganic chemistry) The oxide of lead, PbO, that occurs as the minerals litharge and massicot

(inorganic chemistry) A colourless, odourless, flammable, highly toxic gas

(inorganic chemistry, usually humorous) H₂O, water.

(informal) dihydrogen monoxide (water (H₂O), but not hydrogen peroxide (H₂O₂) or the hydroxyl radical (-OH))

(inorganic chemistry) An unstable binary compound, SO, of sulfur and oxygen.

(inorganic chemistry) nitrous oxide

Alternative spelling of sulfur monoxide