This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
稵 combines 禾 (grain) with 兹, which likely contributes sound. The exact historical development is uncertain.
The left side is grain 禾, and the right side 兹 looks like a tangled plant. Picture a rare, mysterious grain plant with tangled shoots.
For シ, imagine a single grain seed (シ) sprouting from the tangled plant: seed -> シ.