This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 鬛 is uncertain. It contains 髟 (hair) on top, suggesting a meaning related to hair or mane, but the lower component's origin is unclear.
The top 髟 suggests long hair. Imagine a lion's mane flowing down from the top, even though the exact meaning is uncertain.
For リョウ, picture a lion's mane: the 'ryo' in 'lion' is close to リョウ, and the mane ties back to the hair component.