The act of respiring or breathing again, or catching one's breath.
- The act or process of inhaling and exhaling; breathing. Also called ventilation.
- The act or process by which an organism without lungs, such as a fish or plant, exchanges gases with its environment.
- The oxidative process occurring within living cells by which the chemical energy of organic molecules is released in a series of metabolic steps involving the consumption of oxygen and the liberation of carbon dioxide and water.
- Any of various analogous metabolic processes by which certain organisms, such as fungi and anaerobic bacteria, obtain energy from organic molecules.