road with walls on both sides
甬 centers on a passageway or corridor, specifically a road flanked by walls on both sides. It is a rare kanji whose standalone meaning is narrow and architectural.
甬 is thought to depict a passage or corridor, possibly derived from a pictograph of a walled road. The modern form combines 龴 (a lid or cover) with 用, but the exact historical development is uncertain.
The top 龴 looks like a roof or covering, and the bottom 用 suggests a path or use. Imagine a covered walkway with walls on both sides, forming a narrow road.
For ヨウ, picture a yodel echoing between the walls of the road: yodel -> ヨウ, and the sound bounces along the walled passage.
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