flowing full, expanse of water, wide, deep
汪 centers on a large, deep body of water that is full and expansive. The given meanings all describe water that is wide, deep, and flowing abundantly.
汪 combines 氵 (water) with 王, which likely contributes the sound and may suggest a sense of largeness or kingly expanse. The exact historical development is uncertain.
Water 氵 beside a king 王: imagine a king's domain filled with a vast, deep, and flowing expanse of water, like a royal lake that stretches wide.
For オウ, picture a king (王) standing by the water (氵) and letting out a deep, expansive 'Oh!' as he gazes at the wide, full river: Oh -> オウ.
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