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

Downstairs in the basement, a team of covert listeners followed their chatter, gleaning vital insights into Germany's war plans.

From Barron's ● Aug. 5, 2026

“The average videogame customer in America is closing in on 40 years old—we are not a bunch of 15-year-olds eating Doritos in the basement anymore,” he said.

From The Wall Street Journal ● Jul. 30, 2026

Once, someone laid down a broken door, which they had stored in their basement, underneath a car.

From Slate ● Jul. 27, 2026

Read more: Micron was started by a few guys in an Idaho basement.

From MarketWatch ● Jul. 18, 2026

I’m tempted to run downstairs to the basement and clutch Dad’s arm as he sorts laundry, but that’s embarrassing.

From "South of Somewhere" by Kalena Miller

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

From Barron's ● Jul. 9, 2026

"Others tried to get their cars out of the building basements, fearing an aftershock might make things worse."

From BBC ● Jun. 25, 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

With first-time buyers as their intended customers, the company’s innovations included lowering prices by building homes on slabs, instead of digging costly basements.

From Los Angeles Times ● Apr. 14, 2026

We ate sweet pastries in the basements of churches.

From "Native Speaker" by Chang-rae Lee

Related Words

• cellar
• storage
• vault