basement

UK: ˈbeɪsmənt | US: ˈbeɪsmənt

Definition
  1. n. the lowest floor of a building, either entirely or partly below ground level.

Structure
base <foundation>ment <noun suffix>
Etymology

The word "basement" combines "base" (from Old French bas, meaning "low," and Latin basis, meaning "foundation") with the suffix "-ment" (from Latin -mentum, indicating a concrete result or state). Originally used in architecture (18th century), it literally denotes the "lowest foundational part" of a structure. The suffix "-ment" transforms the adjective "base" into a noun, solidifying its modern meaning as a subterranean floor.

Examples
  1. We stored old furniture in the basement.

  2. The basement flooded after heavy rainfall.

  3. She converted the basement into a home theater.

  4. The building’s basement houses the boiler room.

  5. They discovered vintage wine in the basement cellar.