wilds
坰 centers on open, uncultivated land far from settled areas: the wilds or wilderness.
坰 combines 土 (earth, soil) with 冋, which likely contributes the sound. The exact historical development of 冋 is uncertain, but the character is associated with remote, open land.
The left side 土 is earth, and the right side 冋 looks like a distant boundary marker. Picture a vast stretch of empty earth beyond the last marker: the wilds.
For ケイ, imagine a lone kayak (ケイ) drifting through the wilds, with only earth and sky around.
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