The outer wall of the ground story of a building, or of a part of that story, when treated as a distinct substructure. (See Base,
- The substructure or foundation of a building.
- The lowest habitable story of a building, usually below ground level.
- Geology A complex of undifferentiated igneous and metamorphic rocks underlying sedimentary strata.
- Slang The last place or lowest level, as in competitive standings.
- Chiefly New England A public toilet, especially one in a school.