Wu Collection, Lower Volume Radical: Cave (xué) 窵 Kangxi strokes: 16 Page 867, Entry 44 Tang Rhymes (Tangyun) and Collected Rhymes (Jiyun) state: pronounced diao. Explaining Graphs and Analyzing Characters (Shuowen): diao means deep and dark. Du Fu's poetry states: The shadows move, deep and winding, quiet and expansive. Additionally, Collected Rhymes (Jiyun) states: pronounced dao. Meaning is the same.