This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鶓 combines 苗 (seedling) and 鳥 (bird), but the historical origin and meaning are uncertain. It may be a phono-semantic compound, but the exact development is unclear.
A bird 鳥 beside a seedling 苗: perhaps a bird that nests among young plants, but the meaning is unclear.
For ビョウ, imagine a bird pecking at a seedling and making a 'byou' sound: byou -> ビョウ.
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