Hai Collection, Upper Volume
Radical: Horse (mǎ)
Kangxi Strokes: 15
Page 1435, Entry 24
Pronounced jiong.
Expanded Dictionary (Guangyun) and Collected Rhymes (Jiyun) and Rhyme Collection (Yunhui) note the pronunciation as jiong.
According to Jade Chapter (Yupian), this is the same as the character meaning a horse that is fat and in prime condition.
Book of Odes (Shijing), Odes of Lu (Lusong): The stallions are fat and in prime condition, in the wilds beyond the pasture.
Commentary: The belly and body of a fine horse are fat and expanded.
Also, according to Explaining Graphs and Analyzing Characters (Shuowen), it refers to a horse pasture.
Note: The Book of Odes mentions the wilds beyond the pasture (jiong). Mao Commentary states that the area outside the forest is called the pasture (jiong). This pasture is not the same as the character jiong, and the character jiong does not mean a horse pasture. The citation in Explaining Graphs and Analyzing Characters (Shuowen) is incorrect.