This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
閝 combines the gate enclosure 門 with the phonetic component 令. The exact historical development is uncertain, but it likely originally referred to a type of window or opening.
The gate 門 encloses a command 令, like a small window through which orders are given. This may help remember the rare reading きりまど (small window).
For レイ, imagine a ray of light shining through the small window (きりまど) in the gate: ray -> レイ.