barley
麰 centers on barley, a specific type of grain. The meaning is narrow and concrete, referring to the plant or its grain.
麰 combines 麥 (wheat/grain) with 牟, which likely provides the sound and may relate to barley specifically. The exact historical development is uncertain.
The left side 麥 is a grain plant, and the right side 牟 looks like a cow 牛 with a nose ring 厶. Imagine a cow eating barley grain: 麰 is barley.
For ボウ, picture a bow made of barley stalks: bow -> ボウ, and the barley bends like a bow.
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