a solid or hollow tube with long straight sides and two circular ends the same size, or an object shaped like this, often used as a container

Deep-sea divers carry cylinders of oxygen on their backs. 深海潜水员背上背有氧气筒。

the tube-shaped device, found especially in an engine, inside which the part of the engine that causes the fuel to produce power moves up and down

a six-cylinder engine 六汽缸发动机