This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
嚋 is a rare character composed of 口 (mouth) and 壽 (longevity). The exact historical development and original meaning are uncertain.
With 口 (mouth) beside 壽 (longevity), imagine a mouth speaking words of long life, but the exact meaning remains unclear.
For チュウ, picture a long-lived turtle named Chu, whose mouth (口) speaks ancient wisdom: Chu -> チュウ.