In the first part, it gives the meaning of departure and "going up" (to isolation in the mountains? To the heavens above?). In the second part, it gives the meaning of ascension, of reaching a higher goal (grasp the Dao).
I also saw some references to the death of an emperor or king.
I know 登 means ascend, climb, but 假 means fake, suppose or vacation. What's the contribution of 假 to the meaning observed in the Zhuang Zi translations, or even to the death of a king?