waterfowl which flies high but not against the wind
鷁 refers to a specific kind of waterfowl noted for flying high but not against the wind. Its meaning is narrow and descriptive, without broader abstract extensions.
鷁 combines 益 (increase, benefit) and 鳥 (bird), likely as a phono-semantic compound where 益 hints at the sound and 鳥 indicates a bird. The exact historical development is uncertain.
The left side 益 suggests something beneficial or high, and the right side 鳥 is a bird. Picture a beneficial bird that flies high, but only when the wind is favorable.
For ゲキ, imagine a gecko trying to fly like the waterfowl: gecko -> ゲキ, but it can't go against the wind.
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