Left: movement 辶, right: buttock from the side 尸, sheep 羊 (The horned 丷 animal with a backbone 丨 and laterally protruding due to thick wool 三 is a sheep)
Mnemonic
You move like the buttock of a sheep: too late and so slow.
The radical shikabane has the meaning: corpse 尸. But because of its use in tail 尾, buttocks 尻 or urine 尿, it is generally considered to mean "buttocks".
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