This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鞼 combines 革 (leather) with 貴, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side 革 suggests leather, and the right side 貴 suggests something precious. Picture a precious leather item, though its exact meaning is unclear.
For キ, imagine a key made of precious leather: key -> キ, and the leather key is a rare, valuable object.