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

Loop initiates Wex as buy Loop said in its initiation of Wex t hat the fin tech company is firing on all cylinders. —Michael Bloom, CNBC, 28 Apr. 2026

But with incomes below $3 a day, many can no longer afford pricier LPG cylinders and are reverting to stoves that burn firewood, or returning to villages where wood is easier to find. —ABC News, 27 Apr. 2026

The torsion balance and ribbon would twist when the outer masses attracted the inner ones, and physicists measured Big G by tracking the cylinder’s rotation and the resulting gravitational torque. —ArsTechnica, 23 Apr. 2026

Thus, the stockpile is likely stored in cylinders that are not unlike large scuba tanks. —Stephanie Pappas, Scientific American, 23 Apr. 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