The keyword in the names Zhuyin and Zhulong is ''zhu'' "torch; candle; shine upon; illuminate; light up" . One alternate ''Chuci'' name below writes ''zhu'' with the variant Chinese character ''zhuo'' or "quarrel, squabble; distant, far".
Zhuyin uses ''zhu'' as a verb "illuminate; brighten" with ''yin'' "dark; shady; cloudy; overcast", which is the feminine principle of Yin and Yang. ''Yin'' recurs below in the term ''jiuyin'' 九陰 "ninefold darkness" .
Zhulong uses ''zhu'' as a modifier "torch; candle" with ''long'' "Chinese dragon". Compare the homophone ''zhulong'' 燭籠 "lantern" with ''long'' "basket; cage; receptacle".
Early textual references
Zhuyin and Zhulong were first recorded in Chinese classic texts dating from the Han Dynasty and recording myths from the Zhou Dynasty .
The ''Shanhaijing'' "Classic of the Mountains and Seas" records parallel myths about Zhuyin and Zhulong.
"The Classic of Regions Beyond the Seas: The North" section describes Zhuyin 燭陰 on Mount Zhong 鍾山.
The deity of Mount Bell is named Torch Shade. When this deity's eyes look out there is daylight, and when he shuts his eyes there is night. When he blows it is winter, and when the calls out it is summer. He neither drinks, nor eats, nor breathes. If this god does breathe, there are gales. His body is a thousand leagues long. Torch Shade is east of the country of Nolegcalf. He has a human face and a snake's body, and he is scarlet in colour. The god lives on the lower slopes of Mount Bell.
Visser renders Zhuyin as "Enlightener of the Darkness" and translates the commentary of Guo Pu .
'Enlightener' is a dragon; he enlightens the nine ''yin'' ".
"The Classic of the Great Wilderness: The North" section describes Zhulong 燭龍 living on Mount Zhangwei 章尾山.
Beyond the northwest seas, north of the River Scarlet there is Mount Brillianttail. There is a god-human here with a human face and a snake's body, and he is scarlet. He has vertical eyes that are in a straight seam. When this deity closes his eyes, there is darkness. When the deity look with his eyes, there is light. He neither eats, nor sleeps, nor breathes. The wind and the rain are at his beck and call. This deity shines his torch over the ninefold darkness. This deity is Torch Dragon.
The ''yin'' in this ''jiuyin'' 九陰 "ninefold darkness" context explains using the "dragon" name Zhulong instead of "darkeness" name Zhuyin. Guo Pu quotes a legend from a no longer extant ''Shijing'' commentary , "The sky is insufficient to cover the northwest, so there is no ebb and flow of yang and yin. Therefore a dragon carries a torch in its mouth to light up the sky."
The ''Chuci'' "Songs of " mentions Zhulong 燭龍 and Zhuolong 逴龍 with the graphic variant ''zhuo'' or ''chuo'' "argue, quarrel, squabble; far".
The ''Tianwen'' 天問 "Heavenly Questions" section asks about Zhulong. Compare these translations:
*"What land does the sun not shine on and how does the Torch Dragon light it?"
*"Where does the sun not rise, How does the Torch Dragon flame?"
*"The Torch Dragon flares where the sun does not reach "
The ''Dazhao'' 大招 "Great Summons" section uses the alternate name Zhuolong 逴龍 or 趠龍 "distant/quarreling dragon": "In the north are the Frozen Mountain, and the Torch Dragon, glaring red."
The ''Huainanzi'' "Philosophers of Huainan" contains a ''Zhuixing'' 墬形訓 "Treatise on Topography" chapter that refers to Zhulong. This context mentions Xiaoming 宵明 "Night Bright" and Zhuguang 燭光 "Torch Gleam", who were daughters of the legendary .
Lighting Darkness and Candle-Gleam are on an island in the Yellow River; they illumine an area of one thousand li. The Dragon Gate is in the depths of the Yellow River. … The Torch Dragon dwells north of Wild Goose Gate. He hides himself in Abandoned Wings Mountain and never sees the sun. This god has a human face and a dragon body, but no feet.
The commentary of Gao You 高誘 explains, "''Weiyu'' is the name of a mountain … in the shade of the northern limit, the sun cannot be seen." Mount Weiyu 委羽, notes Major, might mean "abandoned wings," "broken wings," "shed feathers," or something else.
The ''Dongmingji'' 洞冥記 "Record of Penetrating the Mysteries", which describes ritual activities of Emperor Wu of Han , is traditionally attributed to Guo Xian 郭憲 but probably dates from around the 6th century. Although this text does not mention Zhuyin or Zhulong, Wu's Daoist advisor Dongfang Shuo 東方朔 describes a mythical northern ''qinglong'' 青龍 "Azure Dragon" with a ''zhu'' 燭 "torch".
… in the year 99 before our era the emperor Wu convoked a meeting of magicians and learned men, at which Tung Fang-soh spoke as follows: "I made a journey to the north pole, and came to a mountain planted with fire, which neither the sun, nor the moon ever illumines, but which is lighted to its uttermost bounds by a blue dragon by means of a torch which it holds in its jaws. I found in that mountain gardens, fields, and parks with ponds, all studded with strange trees and curious plants, and with shrubs which had luminiferous stalks, seeming at night to be lamps of gold. These stalks could be broken off and used as torches, in the light of which the spectres were visible. Ning-fung, the immortal had always eaten this plant, the consequence being that in the darkness of the night there beamed light out of his belly. It is called the herb which pierces darkness.
This namesake torch-like plant is called ''dongmingcao'' 洞冥草 "penetrating the mysteries herb".
Zhuyin 燭陰 or Zhulong 燭龍 was not the only serpent-bodied celestial deity in Chinese folklore, other examples include Pangu, Fuxi, and Nüwa.
The mythic Torch Dragon embodied sunlight. Carr cites a Chinese-language article by Kwang-chih Chang characterizing it with the Eastern Zhou "Transformation Thesis" that natural elements transform out of the bodily parts of mythical creatures.
Major describes the Torch Dragon as "well-known in early Chinese mythology" and suggests it is probably "a mythical interpretation of the aurora borealis."