Kongtong mountain
崆 is a rare kanji that refers specifically to Kongtong mountain. Its standalone meaning is tied to that place name and has no broader conceptual center.
崆 combines 山 (mountain) with 空, which likely contributes the sound. It is used in the place name Kongtong mountain, and the exact historical development is uncertain.
The left side 山 means mountain, and the right side 空 means sky. Picture Kongtong mountain as a mountain so high it touches the empty sky.
For コウ, imagine a mountain so tall it scrapes the sky, and the sound of the wind is a hollow 'koh' echoing around it: koh -> コウ.
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