skin
鞟 centers on the outer covering of an animal: skin, hide, or leather. The given meaning 'skin' is the core idea.
鞟 combines 革 (leather, hide) with 享, which likely contributes the sound. The character is associated with skin or leather.
The left side 革 means leather or hide. The right side 享 looks like a stretched hide being prepared. Together they reinforce the idea of skin.
For カク, imagine a leather worker scraping a hide with a sharp 'kak' sound: kak -> カク, and the hide becomes smooth skin.
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