Cylinder meaning : A surface created by projecting a closed two-dimensional curve along an axis intersecting the plane of the curve. A solid figure bounded by a cylinder and two parallel planes intersecting the cylinder. Any object in the form of a circular cylinder. A cylindrical cavity or chamber in a mechanism, such as the counterpart to a piston found in a piston-driven engine. The space in which a piston travels inside a reciprocating engine or pump. A container in the form of a cylinder with rounded ends for storing pressurized gas; a gas cylinder. An early form of phonograph recording, made on a wax cylinder. The part of a revolver that contains chambers for the cartridges. The corresponding tracks on a vertical arrangement of disks in a disk drive considered as a unit of data capacity. To calender; to press (paper, etc.) between rollers to make it glossy.