This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
筎 combines 竹 (bamboo) with 如, but the historical origin and original meaning are uncertain.
The top is bamboo 竹 and the bottom is 如, but the overall meaning is obscure. Picture an unknown bamboo object labeled with a question mark.
For ジョ, imagine a bamboo shoot labeled with the name 'Jo' to give it an identity: Jo -> ジョ.