This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鐕 combines 金 (metal) with 朁, which likely contributes sound. The exact historical development is uncertain.
The left side is metal 金, and the right side 朁 is obscure. Without a clear meaning, picture a mysterious metal object with an unknown purpose.
For サン, imagine a sun (サン) reflecting off the mysterious metal 金 component, making it gleam.