flowing of tears
潸 centers on the visible, flowing nature of tears: the act of tears streaming down, rather than just the emotion of sadness.
潸 combines 氵 (water) with a phonetic component that likely contributed the sound サン. The water radical reinforces the idea of flowing liquid, specifically tears.
Water 氵 beside a forest 林: imagine rain dripping through the leaves like tears flowing down a face. The lower part suggests the streaks of tears on a cheek.
For サン, picture the sun (サン) shining on a tear-streaked face, drying the flowing tears: sun -> サン.
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tearfully; shedding tears