|a colourless odourless poisonous flammable gas formed when carbon compounds burn in insufficient air and produced by the action of steam on hot carbon: used as a reducing agent in metallurgy and as a fuel. Formula: CO|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
carbon monoxide n.
A colorless, odorless, highly poisonous gas that is formed by the incomplete combustion of carbon or of a carbonaceous material, such as gasoline.
A colorless, odorless gas formed when a compound containing carbon burns incompletely because there is not enough oxygen. It is present in the exhaust gases of automobile engines and is very poisonous. Chemical formula: CO.
Note: Carbon monoxide is usually formed when materials burn; it is found, for example, in automobile exhaust.
Note: Carbon monoxide is a colorless, odorless gas that can be fatal to human beings if inhaled.