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

Or, take the Mr Akpos Dauda room, which is almost something of a library; its white walls are accented with gray and burnt orange details, gas-cylinder bedside lamps, and speckled marble countertops perfect for in-room dining. —Condé Nast, Condé Nast Traveler, 15 Mar. 2026

These long cylinders of glacial ice packed with layers of dust, pollutants, and smoke are frozen time capsules that scientists can use to recreate past environmental conditions. —Nidhi Sharma, Popular Science, 13 Mar. 2026

Nearly 330 million households and over 3 million businesses in India use LPG cylinders. —Priyanka Salve, CNBC, 13 Mar. 2026

The steel pipe's unexpected growth spurt was reported to police early Wednesday by a pedestrian who saw broken pieces of asphalt falling from the cylinder, baffling people passing by and causing traffic congestion. —CBS News, 12 Mar. 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