cantilever (kănˈtəlēvər) [key], beam supported rigidly at one end to carry a load along the free arm or at the free end. A slanting beam fixed at the base is often used to support the free end, as in a common bracket. The springboard is a simple cantilever beam, and the cantilever design is often used for canopies, balconies, sidewalks outside the trusses of bridges, and large cranes such as those used in shipyards. By the use of cantilever trusses, obstructing columns are eliminated in theaters. The cantilever principle is one of the methods that may be used in constructing a bridge.