[{"Bold_text": "noun", "List Items": ["any of various objects or spaces of crescentlike or semicircular outline or section.", "Architecture.(in the plane of a wall) an area enframed by an arch or vault.", "a painting, sculpture, or window filling such an area.", "Fortification.a work consisting of a salient angle with two flanks and an open gorge.", "Ordnance.a towing ring in the trail plate of a towed vehicle, as a gun carriage.", "Ecclesiastical. Luna(def3) Luna(def3)."]}]