dor ‧ mer /ˈdɔːmə $ ˈdɔːrmər/ BrE AmE , ˈdormer ˌwindow British English noun [countable]
[ Date: 1500-1600 ; Language: Old French ; Origin: dormeor 'sleeping room' , from dormir ; ⇨ ↑ dormant ]
a window built into a roof, so that it sticks out from the roof ⇨ ↑ skylight