ˌrespəˈrāshən noun
( -s )
Etymology: Middle English respiracioun, from Latin respiration-, respiratio, from respiratus (past participle of respirare to breathe) + -ion-, -io -ion — more at respire
1.
a. : the placing of air or dissolved gases in intimate contact with the circulating medium (as blood) of a multicellular organism whether by breathing, diffusion through gills or body surface, or other means
most fishes use gills in respiration
b. : a single complete act of breathing
30 respirations per minute
2. : the physical and chemical processes by which an organism supplies its cells and tissues with the oxygen needed for metabolism and relieves them of the carbon dioxide formed in energy-producing reactions and which typically involve osmotic exchange between regions of greater and lesser concentration, mechanical transport in a fluid medium (as blood), and chemical storage by mean of carriers (as hemoglobin) or buffers
3. : any of various energy-yielding oxidative reactions in living matter that typically involve transfer of oxygen and production of carbon dioxide and water as end products — called also cellular respiration ; compare fermentation