a round pipe made of metal, glass, rubber etc, especially for liquids or gases to go through ➔ inner tube, test tube
pipe for liquid[countable]TD
a long hollow object that is usually round:
a toilet roll tube
a narrow container made of plastic or soft metal and closed at one end, that you press between your fingers in order to push out the soft substance that is inside:
a tube of toothpaste
a tube-shaped part inside your body:
in your body[countable]HB
the bronchial tubes
the system of trains that run under the ground in London [= subway American English]
take/catch the tube
Take the tube to Acton.
a tube station
It's best to travel by tube.
if a situation goes down the tubes, it quickly becomes ruined or spoiled:
When Moira turned up, Tess could see all her good work going down the tubes.
the tubeAmerican English spoken
What's on the tube tonight?
the part of a television that produces the picture on the screen [= cathode ray tube]