This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
璹 combines 王 (jade) with 壽, which likely contributes the sound and possibly a meaning related to longevity or preciousness. The exact historical development is uncertain.
The left side 王 suggests jade or a precious stone, and the right side 壽 is associated with longevity. Imagine a treasured jade artifact passed down through generations, but its exact meaning remains unclear.
For シュウ, picture a precious jade shoe (シュウ) that has lasted for ages: shoe -> シュウ, tying the jade component to the sound.