Ascension.
The core foundation of this word comprised the entirety of the Mystic Dao's arduous path; the ascension of the mortal into the mystical, grasping concepts that push the boundaries of imaginations beyond all exceptions, including grasping the mystical elements of the heavens that we're unfathomably, unquestionably profound.
As a mortal being, cultivators grasp the basic principles of the world, such as its general foundations of the world like elemental energy, yin, yang, yin-yang, creation, permanence, mana, consciousness, light, heat, space, time, gravity, celestial phenomena, life, and unity. As an Ascended being, cultivators grasp advanced principles of each, pushing from comprehension and understanding to full-blown manipulation, distortion, and alteration.