LOUVER

or louvre noun Etymology: Middle English lover, from Anglo-French Date: 14th century a roof lantern or turret often with slatted apertures for escape of smoke or admission of light in a medieval building, 2. an opening provided with one or more slanted fixed or movable fins to allow flow of air but to exclude rain or sun or to provide privacy, a finned or vaned device for controlling a flow of air or the radiation of light, a fin or shutter of a ~, ~ed also louvred adjective