basement

American  

[beys-muhnt] / ˈbeɪs mənt /

noun

• basements
  plural

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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Other Word Forms

Noun Inflected Forms

• basements
  plural

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

See Examples For:

basement basements

Elsewhere, a steep flight of gloomily-lit stairs lead to the basement where Morck and his misfits are based – the abandoned shower quarter of the fictional police station which gives them the name Department Q.

From BBC ● Aug. 26, 2026

I trained as best I could, walking four or five hours a day on a walking pad in my parents’ basement, wearing a weighted vest—preparing for a 1,000-year-old pilgrimage by cosplaying as a hamster.

From The Wall Street Journal ● Aug. 25, 2026

Hidden in the basement of a supermarket, the thick smell of sweat hangs heavy in the air as she pushes weights alongside bearded muscle-men.

From Barron's ● Aug. 25, 2026

Over time, erosion along this immense rocky boundary removed huge amounts of material, eventually exposing ancient crystalline basement rocks that can now be seen in the Grand Canyon in southern Arizona.

From Science Daily ● Aug. 21, 2026

Two of his co-workers, who had been sent to the basement of unit 4 to check the status of the reactor, drowned.

From "Meltdown" by Deirdre Langeland

It ushered in a new kind of fun that was fresher, busier and airier than past listservs and chatrooms, the dank basements of internet interaction.

From Salon ● Aug. 23, 2026

The metro is too far from her home and there are no decent shelters or basements nearby.

From Barron's ● Jul. 9, 2026

In an old building, there is a good chance that infrasound is present, particularly in basements where aging pipes and ventilation systems produce low-frequency vibrations.

From Science Daily ● May 3, 2026

In 2020, demand for self-storage spiked as the pandemic caused millions of Americans to relocate or convert basements and garages into living quarters or home offices.

From The Wall Street Journal ● Apr. 15, 2026

Probably just a strip between two real basements.

From "Mockingjay" by Suzanne Collins

Related Words

• cellar
• storage
• vault