Yuán–Míng transitional Daoist layman or cleric resident at Lónghǔshān 龍虎山 (called in his colophon the Hàntán 漢壇, “Altar of the Hàn,” for the lineage’s traditional association with Zhāng Dàolíng’s Hàn-era foundation), hào Qiūshuǐ 秋水. No CBDB record exists. He is known only from his signed imprint-colophon (kānjì 刊記) to Dàdòng yùjīng 大洞玉經 (DZ 7), which he wrote at the age of 89. The colophon records that the Yuán National-University auxiliary-instructor Xióng Tàigǔ 熊太古 (zì Línchū 隣初) brought to Lónghǔshān in 1365 a hand-copied Dàdòng jīng with annotations attributed to a Perfected “Tàixuán Zhào” 太玄趙眞人; that the liànshī 煉師 Zhōu Lánxuě 周蘭雪, then in his eightieth year, re-copied the text and showed it to Gōng; and that Gōng accordingly had his own copy made for personal use and wider transmission. Since the manuscript arrived at Lónghǔshān in 1365 and Gōng was then already an adult reader of the scripture, the colophon itself is to be dated between roughly 1380 and 1410. Gōng closes with an original hymn to the Dàdòng yùjīng and the signature “八十九翁秋水龔德同拜書”. He is otherwise unattested in the Dàozàng corpus and in standard YuánMíng biographical compendia.