the lattice of a window a sill, lintel
欞 refers to the wooden lattice or framework of a window, including the sill and lintel. It is a rare architectural term for the structural grid that holds a window together.
欞 combines 木 (tree/wood) with 靈, which likely contributes the sound. The character is a rare phono-semantic compound for wooden window latticework.
The left side 木 is wood, and the right side 靈 looks like a complex grid with rain 雨 and openings 口口口. Picture a wooden window frame with a lattice pattern that lets in light and air.
For レイ, imagine laying a wooden lattice across the window: lay -> レイ, and the lattice is made of wood.