arrow
笶 centers on an arrow, specifically one made with bamboo. The meaning is straightforward: a projectile shot from a bow.
笶 combines 竹 (bamboo) and 矢 (arrow), directly representing an arrow made from bamboo. This is a straightforward semantic compound.
Bamboo 竹 on top and an arrow 矢 below: picture a bamboo shaft with an arrowhead, making a complete arrow.
For シ, imagine the arrow flying with a sharp 'shee' sound through the air: shee -> シ, and the bamboo arrow hits its target.
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