Solarium may refer to: Sunroom, a room built largely of glass to afford exposure to the sun. A Terrace (building) or flat housetop. The Solarium Augusti, a monumental meridian line (or perhaps a sundial) erected in Rome by Emperor Augustus.
Noun. 1. cavity wall-a wall formed of two thicknesses of masonry with a space between them. wall-an architectural partition with a height and length greater than its thickness; used to divide or enclose an area or to support another structure; the south wall had a small window; the walls were covered with pictures.
Noun[edit] cavity â(plural cavities) 1  A hole or hollow depression. 2  A hollow area within the body (such as the sinuses). ( dentistry) A soft area in a decayed tooth.