This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
醕 combines 酉 (wine vessel) with 亯, which may be a variant of 享 (to offer). The exact historical development is uncertain, but it likely relates to offering wine or something pure.
The left side is a wine vessel 酉, and the right side looks like an offering 亯. Picture a rare, pure wine being offered, though its exact meaning is unclear.
For シュン, imagine a rare wine being offered soon after the harvest: soon -> シュン, and the wine vessel 酉 is ready.