The word "death" is used to describe the death of the emperor. Because the emperor is the symbol of the supreme power in ancient China and represents the "destiny", his death is regarded as a great loss to the country and needs to be expressed with a special taboo.

The word "mourning for the sun" means that the emperor's soul has left the body and ascended to heaven, so his body can be placed in a coffin, held a funeral ceremony and sent to the mausoleum for burial.

The names of emperors' deaths vary from time to time and from historical records. For example, according to historical records, the death of the Han emperor was called "abandoning the dynasty", "abandoning the position" and "sinking". In the Tang Dynasty, the death of the emperor was called "Ascension to Immortal" and "Ascension to Heaven", both of which were myths. In the Ming and Qing Dynasties, the death of the emperor was usually called "accidental death" or "accidental driving", in which "accidental driving" refers to the sudden death of the emperor on the road and is also often used to describe the deaths of other high officials and dignitaries.