This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
籭 combines 竹 (bamboo) with 麗, which likely contributes sound. The exact historical development is uncertain.
The top 竹 suggests bamboo, and the bottom 麗 is a complex shape associated with elegance or a deer. Without a clear meaning, picture a finely woven bamboo sieve or elegant bamboo tool.
For シ, imagine a bamboo sieve (籭) being used to sift fine powder: sieve -> シ, and the bamboo tool does the sifting.