blocked stream, gulf
澥 centers on a body of water that is obstructed or separated from the main flow: a blocked stream or a gulf. The two meanings are connected by the idea of water being cut off or divided.
澥 combines 氵 (water) with 解, which likely contributes both sound and the idea of separating or loosening, together suggesting water that is cut off or divided.
Water 氵 beside 解 (to untie, separate) creates an image of a stream that has been cut off or a gulf that separates two bodies of water.
For カイ, picture a blocked stream that finally breaks free and flows into a wide gulf, like a sigh of relief: 'kai' (カイ) as the water rushes out.
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