It means “great.” The capacity of the mind is as great as that of empty space. If one sits with an empty mind, however, one will be attached to the emptiness characterized by indifference. Empty space can embrace the sun, the moon, stars, plants, the great earth, mountains, rivers, all trees and plants, good and evil people, good and evil dharma, heavens and hells. They are all within this emptiness. The emptiness of human nature is the same.