This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
棙 combines 木 (tree/wood) with 戾, which likely contributes a phonetic element. The exact historical development is uncertain.
The left side 木 suggests wood, and the right side 戾 looks like a complex mechanism. Picture a wooden contraption with twisting parts, hinting at the twisting or mechanical senses sometimes associated with this kanji.
For レイ, imagine a wooden ray of light twisting through the mechanism: ray -> レイ, and the wood twists.