This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
阢 combines the mound radical ⻖ with 兀, but the exact historical development and original meaning are uncertain.
The mound radical ⻖ beside 兀 suggests a steep or rugged terrain, but the meaning is unclear.
For ゴツ, imagine a rugged, rocky mound that looks like a giant's gotz (invented sound): gotz -> ゴツ.
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