MSH: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.,CSP: colorless, odorless gas, CO2, resulting from oxidation of carbon, formed by the tissues; necessary for the respiration cycle of plants and animals.,NCI: A colorless, odorless, incombustible gas resulting from the oxidation of carbon.,NCI: A colorless, odorless gas. It is a waste product made by the body. Carbon dioxide travels in the blood from the body's tissues to the lungs. Breathing out clears carbon dioxide from the lungs.