basement

American  

[beys-muhnt] / ˈbeɪs mənt /

noun

1. a story of a building, partly or wholly underground.

2. (in classical and Renaissance architecture) the portion of a building beneath the principal story, treated as a single compositional unit.

3. the lowermost portion of a structure.

4. the substructure of a columnar or arched construction.

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basement British  

/ ˈbeɪsmənt /

noun

1. 1. a partly or wholly underground storey of a building, esp the one immediately below the main floor Compare cellar

   2. ( as modifier )

      a basement flat

2. the foundation or substructure of a wall or building

3. 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

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Etymology

Origin of basement

First recorded in 1720–30; base ¹ + -ment

Explanation

A basement is a room that's below ground level, underneath the first floor. You might have a laundry room with a washer and dryer in your basement. Some basements are partially under the level of the street, while others are completely below ground. Many, though not all, houses and larger buildings have basements. Some basements are "finished," with carpeting and solid ceilings and walls, but more often they're very basic rooms used for storage. The word dates from 1730, most likely from the Italian basamento, "column base."

Example Sentences

The attraction -- "The Beatles at 3 Savile Row" -- will feature seven floors of never-seen-before archive material and a recreated basement studio where the Fab Four recorded their 1970 "Let It Be" album.

From Barron's • May 11, 2026

The bicycles caught the eye of project director Giovanna Araujo as she was scoping out the basement for sites to bore holes for geotechnical testing.

From Los Angeles Times • May 1, 2026

The business model that once made it an industry maverick—bringing its brand of bargain basement fares coupled with fees for pretty much everything—faced pressure from more intense competition.

From The Wall Street Journal • May 1, 2026

The US justice department says the video also shows Allen "casing the area" at the hotel, on the day before the dinner was held in a basement ballroom there.

From BBC • Apr. 30, 2026

She’s trying to be helpful, but her cheery optimism seems to break Dad, who folds his napkin and clears his dishes before retreating to the basement.

From "South of Somewhere" by Kalena Miller

Related Words

• cellar
• storage
• vault