This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 𠀋 is uncertain. It is a rare character with no widely established etymology.
The shape is simple: a horizontal line with a vertical stroke and a small dot below. Without a known meaning, it is hard to create a reliable mnemonic.
For ジョウ, imagine a tiny dot below a line, like a small 'joe' peeking out: joe -> ジョウ, but the meaning remains unclear.