well sweep
槹 refers to a well sweep, a long pivoting pole used to lift water from a well. Its meaning is narrow and concrete, centered on this traditional irrigation tool.
槹 combines 木 (tree, wood) with 皐, a component associated with height or a high bank. Together they suggest a wooden device for raising water, fitting the well sweep meaning.
A wooden 木 structure with a tall 皐 pivoting arm: picture a well sweep made of wood, rising high to lift water.
For コウ, imagine a well sweep creaking as it lifts water: the sound 'koh' echoes the effort. Koh -> コウ.
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