respiration

noun

1. (uncountable)The process of inhaling and exhaling.

   “In the dead state all is apparently without motion. No agent within indicates design, intelligence, or foresight: there is no respiration; […]”

2. (countable)An act of breathing: a single breath.

   “Gowan snored, each respiration choking to a huddle fall, as though he would never breathe again.”

3. (countable, uncountable)Any similar process in an organism that lacks lungs that exchanges gases with its environment.
4. (countable, uncountable)The process by which cells obtain chemical energy by the consumption of oxygen and the release of carbon dioxide.

   “Near-synonym: metabolism”