This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development is uncertain. The character combines 壽 and 鬼, but the original semantic and phonetic roles are unclear.
No clear meaning is available, so a mnemonic cannot be reliably formed. If needed, note the components: 壽 (longevity) and 鬼 (demon) side by side.
For シュウ, imagine a shoe (シュウ) worn by a demon (鬼) that has lived a long life (壽). The shoe cues シュウ.