cylinder

noun

cyl·​in·​der ˈsi-lən-dər 

1

a

: the surface traced by a straight line moving parallel to a fixed straight line and intersecting a fixed planar closed curve

b

: a solid or surface bounded by a cylinder and two parallel planes cutting all its elements

especially : right circular cylinder see Volume Formulas Table

2

: a cylindrical body or space: such as

a

: the turning chambered breech of a revolver

b(1)

: the piston chamber in an engine

(2)

: a chamber in a pump from which the piston expels the fluid

c

: any of various rotating members in a press (such as a printing press)

especially : one that impresses paper on an inked form

d

: a cylindrical clay object inscribed with cuneiform inscriptions

cylindered

ˈsi-lən-dərd 

adjective

see also on all cylinders

Examples of cylinder in a Sentence

the cylinder of a revolver

Recent Examples on the Web

There’s a pretty sweet list of new and upgraded parts, from brake components like new master cylinders and shoes to a fresh rear-end. —Caleb Jacobs, The Drive, 22 Jan. 2026

The structural complexity of these single-atom-thick cylinders was previously believed to be unattainable through spontaneous natural phenomena. —Mrigakshi Dixit, Interesting Engineering, 22 Jan. 2026

Pressurized Containers This includes fire extinguishers, gas cylinders, oxygen tanks, and propane tanks, according to Ricky Richter, a Media Relations Specialist at the Texas Commission on Environmental Quality. —Melissa Locker, Southern Living, 21 Jan. 2026

If two points are connected by a curve on the sheet of paper, that curve will have the same length on the cylinder. —Elise Cutts, Quanta Magazine, 20 Jan. 2026

Word History

Etymology

Middle French or Latin; Middle French cylindre, from Latin cylindrus, from Greek kylindros, from kylindein to roll; perhaps akin to Greek kyklos wheel — more at wheel

First Known Use

1570, in the meaning defined at sense 1a

Phrases Containing cylinder

• cylinder head
• cylinder seal
• graduated cylinder
• right circular cylinder
• vascular cylinder

Kids Definition

cylinder

noun

cyl·​in·​der ˈsil-ən-dər 

1

: a geometric shape composed of two parallel faces of identical size and shape (as circles) and a curved surface that completely connects their borders

2

: a body (as the piston chamber of an engine, the barrel of a pump, or the part of a revolver which holds the cartridges) shaped like a cylinder

cylindrical

sə-ˈlin-dri-kəl

adjective

cylindrically

-dri-k(ə-)lē

adverb