uneven
嵾 centers on irregularity in terrain: a mountain or landscape that is uneven, jagged, or not smooth.
嵾 combines 山 (mountain) with 參, which likely contributes the sound and may suggest unevenness or irregularity. The exact historical development is uncertain.
The top 山 is a mountain, and the bottom 參 looks like a jagged, uneven shape. Picture a mountain range with irregular peaks and valleys: 嵾 means uneven.
For シン, imagine an uneven mountain path that makes you shin (shin) your way up carefully: shin -> シン, and the rough terrain forces you to climb with your shins.
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