- an open turret or lantern on the roof of a medieval building
- a window or opening furnished with a series of overlapping, horizontal slats arranged so as to admit light and air but shed rainwater outward
- any of these slatsalso louver board
- any similar arrangement of slats or fins, often adjustable, used to control ventilation, light intensity, etc.
- a ventilating slit
Origin of louverMiddle English luver from Middle French lover from Middle Dutch love, gallery (in a theater), akin to Old High German louba: see lodge