cylinder

A cylinder is a three dimensional shape with two round shapes at either end and two parallel lines connecting the round ends. (noun)

An example of cylinder is a can of tomato soup.

See cylinder in Webster's New World College Dictionary

noun

Geom.
1. in geometry, a solid figure consisting of two parallel bases in the form of congruent, closed curves joined by a smooth, continuous, closed surface; specif., such a figure () having circular bases and a surface perpendicular to the bases
2. the surface of such a solid
anything having the shape of a cylinder, whether hollow or solid; specif.,
1. the turning part of a revolver, containing chambers for cartridges
2. the chamber in which the piston moves in a reciprocating engine
3. the barrel of a pump
4. on a printing press, a roller carrying the printing plates or the part receiving the impression
5. a large, hollow, cylindrical clay object with cuneiform inscriptions, or a similar small stone worn on the wrist in ancient times in the Middle East

See cylinder in American Heritage Dictionary 4

cyl·in·der

noun

Mathematics
a. The surface generated by a straight line intersecting and moving along a closed plane curve, the directrix, while remaining parallel to a fixed straight line that is not on or parallel to the plane of the directrix.
b. The portion of such a surface bounded by two parallel planes and the regions of the planes bounded by the surface.
c. A solid bounded by two parallel planes and such a surface, especially such a surface having a circle as its directrix.
A cylindrical container or object.
Engineering
a. The chamber in which a piston of a reciprocating engine moves.
b. The chamber of a pump from which fluid is expelled by a piston.
The rotating chamber of a revolver that holds the cartridges.
Any of several rotating parts in a printing press, especially one that carries the paper.
Archaeology A cylindrical stone or clay object with an engraved design or inscription.