skeleton
骷 centers on the hard framework of a body: a skeleton. It is a specific anatomical term for the bony structure left after decay.
骷 combines 骨 (bone) with 古, which likely contributes the sound. The character is used specifically for a dried skeleton.
The left side 骨 means bone, and the right side 古 suggests something old. Picture an old, dried-up skeleton where only the bones remain.
For クウ, imagine a skeleton in a cool, dark cave: cool -> クウ, and the old bones lie there.
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