basement

plural basements

1. architectureA floor of a building below ground level.

   1 more example

   Turning back, then, toward the basement staircase, she began to grope her way through blinding darkness, but had taken only a few uncertain steps when, of a sudden, she stopped short and for a little stood like a stricken thing, quite motionless save that she quaked to her very marrow in the grasp of a great and enervating fear.

   1914 November, Louis Joseph Vance, “An Outsider […]”, in Munsey’s Magazine, volume LIII, number II, New York, N.Y.: The Frank A[ndrew] Munsey Company, […], published 1915, →OCLC, chapter III (Accessory After the Fact), page 382, column 1

   1. abbreviationellipsisarchitectureEllipsis of semi-basement, a floor mostly below grade
2. geographyA mass of igneous or metamorphic rock forming the foundation over which a platform of sedimentary rocks is laid.
3. informalhobbiesLast place in a sports conference's standings.