Tubes

Tubes

The definition of a tube is a pliable container with a screw cap at one end to keep it closed. An example of tube is the container that toothpaste comes in. A small flexible cylindrical container sealed at one end and having a screw cap at the other, for pigments, toothpaste, or other pastelike substances. Tubes are used in applications such as medical devices that require a precise outside diameter. The outside diameter is important since it will indicate how much it can hold as a stability factor. Pipes are used for transporting gasses or liquids making it important to know the capacity.

The "Tube" is a slang name for the London Underground, because the tunnels for some of the lines are round tubes running through the ground. The Underground serves 270 stations and over 408 km of track.