I looked up several dictionaries, basically referring to chicken thigh meat or breast and abdomen meat. What's upstairs is chicken feet. The following is what the dictionary says, posted for reference.

1, according to Shandong Literature and Art Publishing House 1986 edition of A Dream of Red Mansions Dictionary (edited by Yang Weizhen and Guo Rongguang).

Chicken melon: Chicken thigh meat or breast and abdomen meat is called chicken melon because it is long and round and looks like melon. (4 1 time)

2. According to A Dream of Red Mansions Dictionary edited by Zhou, published by Guangdong People's Publishing House (1987).

Chicken melon: refers to the muscle or belly of chicken. Because it is long and round, it looks like a melon, so it is called chicken melon. (4 1 time)

3. According to A Dream of Red Mansions Dictionary (edited by Feng Qiyong Li Xifan), Culture and Art Press 1990.

Jianghuai people call animal leg meat "melon seeds", such as beef leg melon seeds, sheep leg melon seeds, pig leg melon seeds and chicken leg melon seeds, which are named because their tendons are like melons. A piece of cloud chicken melon, that is, diced chicken, fried chicken also uses leg melon seeds. However, the cooking method in Tong's Dietary Rules is different: "Pheasant melon: boneless, cut into pieces, and stir-fried with pickled melon, winter bamboo shoots, melon kernels, ginger, vegetable oil, sweet sauce or pepper." The "melon" here also contains ingredients with the meaning of pickled melon and melon seeds. (4 1 time)