This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
梈 combines 木 (tree/wood) with 亨, which may have contributed a phonetic element. The exact historical development is uncertain.
The left side is a tree 木, and the right side 亨 looks like a tall structure. Picture a wooden frame or a large bow made from a tree, matching the kun-reading hint of a wooden bow.
For ホウ, imagine a wooden bow being drawn back with a deep, resonant 'hou' sound as it releases: hou -> ホウ.