- a story of a building, partly or wholly underground.
- (in classical and Renaissance architecture) the portion of a building beneath the principal story, treated as a single compositional unit.
- the lowermost portion of a structure.
- the substructure of a columnar or arched construction.
- a partly or wholly underground storey of a building, esp the one immediately below the main floorCompare cellar
- (as modifier)a basement flat
- the foundation or substructure of a wall or building
- geology a part of the earth’s crust formed of hard igneous or metamorphic rock that lies beneath the cover of soft sedimentary rock, sediment, and soil