This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
瓉 is a rare character. It visually contains 王 (jade) on the left and 賛 on the right, but the exact historical development is uncertain.
The left side is 王 (jade), and the right side is 賛 (approve). Picture a rare jade artifact that needs approval to be displayed, but its true meaning remains hidden.
For サン, imagine a sunlit jade artifact being approved: sun -> サン, and the jade 王 shines under the approving light.