American Heritage® Dictionary of the English Language, Fourth
Edition - n. An oxide with each molecule containing one oxygen
atom. GNU Webster's 1913 - n. (Chem.) An oxide containing one
atom of oxygen in each molecule. - n. an oxide containing just
one atom of oxygen in the molecule - Formed as mon- + oxide;
compare the earlier dioxide, pentoxide, and tetroxide.
(Wiktionary) “And I also proved that carbon monoxide is not
deadly by sitting in a running vehicle for an hour.” “I dunno
that that's so -- carbon monoxide is almost exactly the same
density as air, and the National Fire Protection Association
code is fine with putting a detector on the ceiling so long as
it's someplace you can hear it.” “Carbon monoxide is a natural
component of the atmosphere as well.” “Despite the danger,
dihydrogen monoxide is often used: as an industrial solvent and
coolant. in nuclear power plants. in the production of
styrofoam. as a fire retardant. in many forms of cruel animal
research. in the distribution of pesticides.” “D