the pivots, at the top and bottom of a Chinese door, on which the door turns
椳 refers specifically to the wooden pivot pins at the top and bottom of a traditional Chinese door, on which the door swings. Its meaning is narrow and technical, centered on that door-hinge mechanism.
椳 combines 木 (wood) with 畏, which likely contributes a phonetic element. The character is a specific term for wooden door pivots, and its structure reflects the material and a sound component.
The left side 木 (wood) points to the material, and the right side 畏 looks like a complex hinge mechanism. Picture a wooden door with a carved pivot pin that fits into a socket, allowing it to turn smoothly.
For ワイ, imagine the door pivot making a 'why' sound as it creaks: why -> ワイ. The wooden hinge asks 'why' it must bear the weight.
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