Meaning of TUBE in English

I. tube 1 S3 W3 /tjuːb $ tuːb/ BrE AmE noun

[ Date: 1600-1700 ; Language: French ; Origin: Latin tubus ]

1 . PIPE FOR LIQUID [countable] a round pipe made of metal, glass, rubber etc, especially for liquids or gases to go through ⇨ ↑ inner tube , ↑ test tube

2 . [countable] a long hollow object that is usually round:

pasta tubes

a toilet roll tube

3 . CONTAINER [countable] 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

4 . IN YOUR BODY [countable] a tube-shaped part inside your body:

the bronchial tubes

5 . TRAINS the tube British English the system of trains that run under the ground in London SYN subway American English

take/catch the tube

Take the tube to Acton.

a tube station

by tube

It’s best to travel by tube.

6 . go down the tubes informal 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.

7 . TELEVISION the tube American English spoken the television:

What’s on the tube tonight?

8 . ELECTRICAL EQUIPMENT [countable] technical the part of a television that produces the picture on the screen SYN cathode ray tube

II. tube 2 BrE AmE verb [intransitive]

to float on a river on a large ↑ inner tube for fun

Longman Dictionary of Contemporary English.      Longman - Словарь современного английского языка.