river in Shandong province
灉 is a rare kanji that refers specifically to a river in Shandong province. Its meaning is a proper name with no broader conceptual center.
灉 combines the water radical 氵 with 雝, which likely provides the sound. The character was created as a proper name for a specific river.
The water radical 氵 tells you this is a river. The right side 雝 is complex and distinctive, like the winding path of a specific river in Shandong.
For ヨウ, imagine a yo-yo floating down this Shandong river: yo -> ヨウ, and the water carries it along.
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