Noun
1. the metabolic processes whereby certain organisms obtain energy from organic moelcules; processes that take place in the cells and tissues during which energy is released and carbon dioxide is produced and absorbed by the blood to be transported to the
2. a single complete act of breathing in and out;
"thirty respirations per minute"3. the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation