This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 籆 is uncertain. It visually combines 竹 (bamboo) and 蒦, but the original semantic and phonetic roles are unclear.
The top 竹 suggests bamboo, and the bottom 蒦 is a complex shape. Without a clear meaning, picture an old bamboo tool whose purpose is now forgotten.
For ワク, imagine a bamboo frame (枠, わく) that holds the mysterious 蒦 component together: 枠 -> ワク, and the bamboo top 竹 reinforces the frame image.