This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
墢 combines 土 (earth) with 發, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side is earth 土, and the right side is a complex shape 發. Without a clear meaning, picture earth being moved or opened up by something forceful.
For ハツ, imagine a hat sitting on the earth: hat -> ハツ, and the earth component 土 is underneath.
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