This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
櫲 is a rare character combining 木 (tree) with 豫. The exact historical development is uncertain, but it likely names a type of tree, possibly related to the camphor tree (くすのき).
A tree (木) with a complex right side (豫) that looks like a sprawling camphor tree. Picture a large, ancient camphor tree with twisting branches.
For ヨ, imagine a yo-yo hanging from the branches of this tree: yo -> ヨ, and the tree is a camphor tree.