loose, dishevelled, pore, cavity in overboiled daikon
鬆 centers on a state of looseness or lack of firmness, whether in texture, appearance, or structure. The specific sense of a cavity in overboiled daikon is a natural extension of that porous, loose quality.
鬆 combines 髟 (hair) with 松 (pine tree). The character likely expresses the idea of looseness or dishevelment through the image of hair as loose as pine needles, but the exact historical development is uncertain.
The top 髟 suggests hair, and the bottom 松 is a pine tree. Imagine hair so loose and disheveled it looks like the fluffy, open texture of pine needles—full of pores and cavities.
For ショウ, picture a show of loose, disheveled hair on stage: show -> ショウ, and the hair is as loose as an overboiled daikon.
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