This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
篗 combines 竹 (bamboo) with 隻, but the exact historical development and original meaning are uncertain.
Bamboo 竹 over 隻 suggests a bamboo tool or container, but the exact meaning is unclear.
For ワク, imagine a bamboo frame (枠, わく) holding the shape of 篗: 枠 -> ワク, and the bamboo top reinforces the frame.