noun
openable panel in a door; door panel that can be opened
Architectural term for a small hinged or sliding panel set within a larger door, allowing ventilation or a view without opening the whole door.
古い日本家屋の玄関には、無双窓が付いていることがある。
The entrance of old Japanese houses sometimes has an openable panel in the door.
Standard kanji spelling for this architectural term.
Variant kanji spelling; less common.
The exact derivation is uncertain; the kanji 無双 (peerless) may refer to the unique dual-function design of the panel.