This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
嵤 combines 山 (mountain) with a phonetic component that may be related to 榮 or similar forms. The exact historical development is uncertain.
The kanji has 山 at the bottom, suggesting a mountain, but the overall meaning is unclear. Picture a mysterious mountain with a hidden name.
For ケイ, imagine a mountain shaped like the letter K: K mountain -> ケイ.