This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
桻 combines 木 (tree) with 夆, but the exact historical development and original meaning are uncertain.
The left side 木 suggests a tree, and the right side 夆 is a component shared with peak-related kanji. Picture a tree at the peak of a hill, but remember the meaning is uncertain.
For ホウ, imagine a tree at the peak of a hill, and a strong wind howls through its branches: howl -> ホウ.