This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
蟚 combines 虫 (insect) with 彭, which likely contributes sound. The exact historical development is uncertain.
The top 彭 looks like a drum on a stand, and the bottom 虫 is an insect. Imagine a tiny insect drumming on a drum, but the meaning remains uncertain.
For ホウ, picture a hollow drum sound: 'hoh' -> ホウ, as the insect drums on the 彭 component.
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