Vacuous li

Also apical pulse. The place below the nipple at which a throbbing can be felt and said to be the collecting place of ancestral qì. Vacuous lǐ corresponds in channel theory to the great network vessel of the stomach, and since stomach qì is a foundation of human life and is the source of ancestral qì in the chest, it reflects the state of ancestral qì and stomach qì.

Etymology

Chin 虚 xū, vacuous, empty, weak; 里 lǐ, area, township, village; unit of distance. Possibly from the Gk. khylos.