What does qi (chi) means??? What are other synonims?

By inhaling clear qi from natural air and exhaling turbid qi out of the body, it exchanges the qi between the interior and the exterior of the body. Depending on the regulation of lungs, the qi (vital energy) can circulate smoothly throughout the body, and therefore, a normal state of internal metabolism is ensured. However, respiration does not merely depend on the lungs functioning; the kidneys also coordinate it. In order to keep the qi exchange effective, the inhaled and refined qi must flow down and be absorbed by the kidneys properly. The astringent or grasping and holding function of the kidneys ensures the lungs to receive and circulate downward the qi. In this way, the former helps coordinate respiration while the latter controls respiration.