陀

Left mound radical - the side-form of 阜, depicting a stepped hillside. The indexing radical, marking 陀 as terrain-related (originally 'slope, uneven mountain ground'). The left-阝 family includes 阵 (formation), 险 (steep), 阳 (sunny slope) - all hill-and-rampart vocabulary. Distinct from the right-阝 'city' radical.

Right 它 supplies the sound - tā shifting to tuó through historical drift. 它 originally pictured a snake (now written 蛇). Same phonetic core links 陀 with 驼 (camel), 沱 (tears flowing), 砣 (counterweight) - all sharing the tuó reading. Often appears in transliterations like 弥勒陀.