billowy clouds, deep and broad
泱 centers on vast, expansive water imagery: billowy clouds and deep, broad expanses. Both meanings describe something wide, deep, and filled with water or moisture.
泱 combines 氵 (water) with 央, which likely contributes the sound and the idea of a central expanse. The exact historical development is uncertain.
Water 氵 spreads out from the center 央, creating a deep, broad expanse like billowy clouds over a vast sea.
For オウ, imagine a deep, broad ocean wave swelling up: the sound 'oh!' (オウ) escapes your lips as you see its vastness.