Transom :  (noun)
1: a window above a door and hinged to a transom [syn: transom window, fanlight]
2: a horizontal crosspiece across a window or separating a door from a window over it [syn: traverse]

air duct, air hole, air passage, air shaft, air tube, airway, bay, bay window, blowhole, bow window, breathing hole, casement, casement window, cross bitt, crossarm, crossbar, crosspiece, doubletree, fan window, fanlight, grille, lancet window, lantern, lattice, light, louver, louver window, louverwork, naris, nostril, oriel, pane, picture window, port, porthole, rose window, shaft, singletree, skylight, spilehole, spiracle, swingletree, touchhole, transept, transversal, transverse, traverse, vent, ventage, venthole, ventiduct, ventilating shaft, ventilator, whippletree, wicket, wind tunnel, window, window bay, window glass, windowpane,