In architecture — particularly in the architecture of cathedrals and churches — the clerestory {kleer'-stohr-ee} is a windowed wall that rises above the roofs of adjacent walls, giving light free passage into the interior. In Romanesque churches the clerestory often contains a narrow passageway that is distinct from the arcaded wall passage, the triforium, immediately below. In Gothic churches the fully developed flying buttress enabled architects to fill the entire clerestory with elaborate stained glass.