The diffusion of gases from an area of higher concentration to an area of lower concentration, especially the exchange of oxygen and carbon dioxide between an organism and its environment. In plants, gas exchange takes place during photosynthesis. In animals, gases are exchanged during respiration.
noun 1. a district yielding natural gas.
[gas-fahyuh rd] /ˈgæsˌfaɪərd/ adjective 1. using a gas for fuel. adjective using a combustible gas as fuel
noun 1. a person who installs gas pipes and apparatus in buildings.
noun 1. the work or business of a gas fitter. 2. gas fittings, fittings for the use of illuminating gas.