This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
嶛 combines 山 (mountain) with 尞, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side 山 suggests a mountain, and the right side 尞 looks like a complex structure. Picture a steep, rugged mountain peak that is difficult to describe.
For リョウ, imagine a lone mountain climber named Ryo standing on the peak: Ryo -> リョウ, and the mountain 山 is his domain.