This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 臹 is uncertain. It visually combines 至 and 成, but the original semantic and phonetic roles are unclear.
Since the meaning is unclear, focus on the shape: 至 (arrive) and 成 (become) together might suggest reaching completion, but this is only a visual guess.
For シュウ, imagine arriving (至) at a shoe (シュウ) shop to become (成) a shoe collector: shoe -> シュウ.