cyl·in·der / ˈsiləndər/ • n. a solid geometric figure with straight parallel sides and a circular or oval section. ∎  a solid or hollow body, object, or part with such a shape. ∎  a piston chamber in a steam or internal combustion engine. ∎  a cylindrical container for liquefied gas under pressure. ∎  a rotating metal roller in a printing press. ∎  Archaeol. a cylinder seal.DERIVATIVES: cy·lin·dric / səˈlindrik/ adj.cy·lin·dri·cal / səˈlindrikəl/ adj.cy·lin·dri·cal·ly / səˈlindrik(ə)lē/ adv.

cylinder Solid figure or surface formed by rotating a rectangle using one side as an axis. If the vertical height is h and the radius of the base r, then the volume is πr²h and the curved surface area 2πrh.

cylinder or rotary valve. A special type of valve in brass instr., in much use in some European countries but in Brit. and USA applied only to the Fr. hn. The term is sometimes used for any kind of valve, e.g. It. trombone a cilindri (valve tb.).

cylinder XVI. — L. cylindrus — Gr. kúlindros roller, f. kulindein roll.
So cylindrical XVII. f. modL. cylindricus — Gr. kulindrikós.