egynyílásos
Egynyílásos is a Hungarian architectural term describing an opening in a wall that consists of a single leaf or sash. It is used to classify windows, doors, arches, and other openings in plans and technical drawings, and it marks a contrast with openings that have two or more leaves (two-leaf, three-leaf, or multi-leaf configurations).
In practice, an egynyílásos ablak is a single-leaf window, typically with one frame and a movable sash,
The term is most commonly encountered in Hungarian architectural literature, heritage surveys, technical catalogs, and renovation