A recess or projection, with a dome or vault, at the east end of a church; an apse.
Either of the points in the elliptical orbit of a planet or comet where it is closest or furthest from the sun; perihelion or aphelion; an apside
A Christian church building having a nave with a semicircular apse, side aisles, a narthex and a clerestory.
A Roman Catholic church or cathedral with basilican status, an honorific status granted by the pope to recognize its historical, architectural, or sacramental importance.