The floor of a building which is partly or entirely below ground level
(Chiefly British) a basement, or part of a basement, used as a complete residence.
A storey of a building partly below ground level
A storey below a basement
A basement with windows and its own entrance.
A store or part of a store where goods are sold cheaply
A thin, delicate membrane of protein fibres and mucopolysaccharides separating an epithelium from underlying tissue