Respiration (noun)

1. The act of breathing, especially the exchange of oxygen and carbon dioxide in the body.
2. The process of inhaling and exhaling air in order to obtain oxygen and release carbon dioxide.

Origin:

From the latin word "respiratio" meaning "breathing".

Examples:

1. The study of respiration is essential to understanding how the body functions.
2. The patient's respiration rate is normal.
3. The athletes are trained to improve their respiration.
4. The respiration system of plants is different than animals.
5. The machine is measuring the patient's respiration rate.