This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 桊 is uncertain. It visually combines 龹 and 木, but the original semantic or phonetic role of these components is unclear.
With no clear meaning, picture a wooden (木) scroll-like top (龹) as a mysterious object whose purpose is unknown.
For ケン, imagine a wooden (木) scroll (龹) that belongs to a man named Ken: Ken -> ケン.
—