cylinder

American  

[sil-in-der] / ˈsɪl ɪn dər /

noun

1. Geometry. a surface or solid bounded by two parallel planes and generated by a straight line moving parallel to the given planes and tracing a curve bounded by the planes and lying in a plane perpendicular or oblique to the given planes.

2. any cylinderlike object or part, whether solid or hollow.

3. the rotating part of a revolver, containing the chambers for the cartridges.

4. (in a pump) a cylindrical chamber in which a piston slides to move or compress a fluid.

5. (in an engine) a cylindrical chamber in which the pressure of a gas or liquid moves a sliding piston.

6. (in certain printing presses)

   1. a rotating cylinder that produces the impression and under which a flat form to be printed from passes.

   2. either of two cylinders, one carrying a curved form or plate to be printed from, that rotate against each other in opposite directions.

7. (in certain locks) a cylindrical device for retaining the bolt until tumblers have been pushed out of its way.

8. (in a screw or cylindrical gear) an imaginary cylindrical form, concentric to the axis, defining the pitch or the inner or outer ends of the threads or teeth.

9. Computers. the tracks of a magnetic disk that are accessible from a single radial position of the access mechanism.

10. Textiles. the main roller on a carding machine, especially the roller covered with card clothing that works in combination with the worker and stripper rollers in carding fibers.

11. Archaeology. a cylindrical or somewhat barrel-shaped stone or clay object bearing a cuneiform inscription or a carved design, worn by the Babylonians, Assyrians, and kindred peoples as a seal and amulet.

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verb (used with object)

1. to furnish with a cylinder or cylinders.

2. to subject to the action of a cylinder or cylinders.

cylinder British  

/ ˈsɪlɪndə /

noun

1. a solid consisting of two parallel planes bounded by identical closed curves, usually circles, that are interconnected at every point by a set of parallel lines, usually perpendicular to the planes. Volume base area × length

2. a surface formed by a line moving round a closed plane curve at a fixed angle to it

3. any object shaped like a cylinder

4. the chamber in a reciprocating internal-combustion engine, pump, or compressor within which the piston moves See also cylinder block

5. the rotating mechanism of a revolver, situated behind the barrel and containing cartridge chambers

6. printing any of the rotating drums on a printing press

7. Also called: cylinder seal.  a cylindrical seal of stone, clay, or precious stone decorated with linear designs, found in the Middle East and Balkans: dating from about 6000 _bc

8. Also called: hot-water cylinder.  a vertical cylindrical tank for storing hot water, esp an insulated one made of copper used in a domestic hot-water system

9. working or performing at full capability

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verb

1. (tr) to provide (a system) with cylinders

cylinder Scientific  

/ sĭl′ən-dər /

1. A three-dimensional surface or solid object bounded by a curved surface and two parallel circles of equal size at the ends. The curved surface is formed by all the line segments joining corresponding points of the two parallel circles.

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cylinder Idioms  

1. see firing on all cylinders.

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Other Word Forms

• cylinder-like adjective
• cylinderlike adjective

Etymology

Origin of cylinder

1560–70; < Latin cylindrus < Greek kýlindros roller, cylinder, akin to kylíndein to roll

Explanation

A cylinder is a solid shape bounded by a cylindrical shape and two parallel circular bases. Confused yet? Just picture a soda can or one of those mailing tubes with a round bottom and a lid. The word cylinder is certainly mired in a whole lot of technical terms. It's one of the basic geometric shapes, as well as a key piece of engineering — such as the cylinders in an engine, which are the chambers where the pistons move. So don't worry if you don't quite get it. You have to be "running on all cylinders" to get what this word is all about.

Example Sentences

This rocking chair is equal parts dramatic and functional, featuring a stacked cylinder back, rocker frame and arm rests in a black glossy finish.

From Los Angeles Times • Apr. 17, 2026

While domestic cooking gas prices were raised by a modest 7% in early March, the analyst expects OMC losses to have widened to 400 rupees per cylinder following April increases in Saudi oil product prices.

From The Wall Street Journal • Apr. 7, 2026

She is attached to an oxygen cylinder at all times, waiting for a double lung transplant.

From BBC • Mar. 24, 2026

"I have been trying to book a gas cylinder for days now but I have had no luck so far. This has thrown all our plans in disarray," Prasad, 43, told AFP.

From Barron's • Mar. 20, 2026

He used an explosion to drive the air out of a cylinder through a valve; then, when the hot gases cooled, a piston was sucked downwards, raising a weight.

From "The Invention of Science" by David Wootton

Related Words

• barrel