n. In geometry: A solid which may be conceived as generated by the revolution of a rectangle about one of its sides: specifically called a right cylinder.n. In mech.: That chamber of a steam-engine in which the force of steam is exerted on the piston. See steam-engine.n. The barrel of an air-pump.n. A hollow metallic roller forming part of certain printing-machines.n. The bore of a gun.n. That part of a revolver which contains the chambers for the cartridges.n. The central well around which a winding staircase is carriedn. The body of a pump.n. In a loom, a revolving part which receives the cards. In the Jacquard loom it is a square prism revolving on a horizontal axis.n. In a carding-machine, a clothed barrel larger than an urchin or a doffer. See cut under carding-machine.n. In an electrical machine, a barrel of glass.n. In ordnance, a wooden bucket in which a cartridge is carried from the magazine to the gun.n. A garden- or field-roller.n. In antiquity, a cylindrical or somewhat barrel-shaped stone, bearing a cuneiform inscription or a carved design, worn by the Babylonians, Assyrians, and kindred peoples as a seal and amulet. Great numbers of such cylinders have been found, and also of Phenician imitations of them.n. An old portable timepiece of the class of sun-dials.n. [capitalized] In conchology, a genus of gastropods: same as Oliva.To press under a cylinder or between cylinders.