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joist

American  
[joist] / dʒɔɪst /

noun

  1. any of a number of small, parallel beams of timber, steel, reinforced concrete, etc., for supporting floors, ceilings, or the like.


verb (used with object)

joists, present (3rd person singular) joisted, past participle, past joisting present participle
  1. to furnish with or fix on joists.

joist British  
/ dʒɔɪst /

noun

  1. a beam made of timber, steel, or reinforced concrete, used in the construction of floors, roofs, etc See also rolled-steel joist

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

verb

  1. (tr) to construct (a floor, roof, etc) with joists

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

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Etymology

Origin of joist

1325–75; Middle English giste < Old French < Latin *jacitum support, noun use of neuter of Latin jacitus (past participle of jacēre to lie), equivalent to jaci- variant stem + -tus past participle suffix

Explanation

A joist is a support that strengthens floors and ceilings in a house. Joists run horizontally, connecting with the studs in walls to give buildings a solid frame. You can't see the joists in a finished house or building, because they're inside the foundation, walls, or ceiling. Joists are usually made of wood, although they can also be concrete or steel, materials strong enough to provide support. Ceiling joists often connect to beams, which tend to be larger and run perpendicular to joists. Joist comes from the Old French word giste, "beam supporting a bridge," from the Latin iacere, "to rest."

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Vocabulary lists containing joist

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

You’ll also want to protect your investment by using the newer joist tape products.

From Seattle Times Apr. 30, 2024

The home was badly damaged and every roof joist was left burnt by the fire.

From BBC Dec. 20, 2022

Put it in a ceiling joist or reinforced that particular area.

From Salon Jul. 10, 2022

This same corrosion can be happening with any of the joist hangers and other structural framing connectors.

From Washington Post May 24, 2022

His concentration broken, he stepped awkwardly upon a joist and tripped heavily into the thick dust.

From "Redwall" by Brian Jacques

The often-expansive data-center buildings typically have steel frames made up of wall pillars, roof joists and roof sheeting.

From The Wall Street Journal Jun. 29, 2026

When I took on this house, I was thinking, how can we highlight components of it, from the ceiling to the roof to the joists, as if it were an art piece?

From Los Angeles Times Aug. 11, 2025

The joists used for the first and second-story floors were 2-by-12s cut from Southern Yellow Pine trees.

From Seattle Times Apr. 8, 2024

Inside Mr. Zulkibli’s 50-foot-high birdhouse, wooden joists crisscross the ceilings, creating places for birds to make their nests.

From New York Times Apr. 2, 2024

Uncle Drum has put a sheet of plywood over those joists.

From "The Truth as Told by Mason Buttle" by Leslie Connor

She is a tank ribbed, joisted, stayed, but she is no greater mystery than a tank. 

From Notes on Life and Letters by Conrad, Joseph

The tunnel vault and the joisted ceiling were equally well suited to the long galleries of Assyrian palaces.

From A History of Art in Chaldæa & Assyria, v. 1 by Armstrong, Walter, Sir

In the windows sat stately dames and beautiful maidens, featly adorned, and gazed down at the joisting of the warriors, till that the king himself began to tilt with his kinsmen.

From The Fall of the Niebelungs by Armour, Margaret

"I look to see some handsome joisting," said Don Pedro, who rode with the King of Majorca upon the right of the prince, while Chandos was on the left.

From The White Company by Doyle, Arthur Conan, Sir

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