Yin Collection, Middle Volume
Radical: Mountain (shān)
岨
Kangxi strokes: 8
Page 309, Entry 18
Pronounced qu
Pronounced qu, same as the character for a stony hill (jū).
As defined in the Analytical Dictionary of Characters (Shuowen Jiezi), a mountain of stone topped with soil.
In the Book of Odes (Shijing), in the Zhou South section: Climbing that stony hill. Currently written as the character for a stony hill (jū).
In the Chu Commentary (Zhu zhuan), a stony mountain topped with soil is called a stony hill (jū).
In the Correction of Character Orthography (Zhengzitong), the character for a rugged mountain (jǔ) is written as the character for a stony hill (jū); the meanings are interchangeable.
Also, in the Five Sounds Rhyme Dictionary (Wuyin Jiyun), pronounced zu; sound matches the word for an obstruction (zǔ). It describes the rugged shape of a mountain.