tjuːb
tuːbpipe
1 [countable] a long hollow pipe made of metal, plastic, rubber, etc, through which liquids or gases move from one place to another see also cathode ray tube, inner tube, test tube2 [countable] a hollow object in the shape of a pipe or tubea bike's inner tubethe cardboard tube from the centre of a toilet rollcontainer
3 [countable] tube (of something) a long narrow container made of soft metal or plastic, with a lid, used for holding thick liquids that can be squeezed out of ita tube of toothpaste4 (Australian English, informal) a can of beera tube of lagerpart of body
5 [countable] a part inside the body that is shaped like a tube and through which air, liquid, etc. passesbronchial tubesThe oesophagus is the tube leading from the throat to the stomach.underground railway
6 (also The Tube™) [singular] (British English) the underground railway system in Londona tube station/trainWe came by tube.She caught the wrong tube (= tube train).television
7 the tube [singular] (North American English, informal) the televisionin ear
8 (North American English) (British English grommet) [countable] a small tube placed in a child's ear in order to drain liquid from itIdioms
go down the tube/tubes
(informal) (of a plan, company, situation, etc.) to failThe education system is going down the tubes.
Usage note: underground / subway / metro / tubeA city’s underground railway/railroad system is usually called the underground (often the Underground) in British English and the subway in North American English. Speakers of British English also use subway for systems in American cities and metro for systems in other European countries. The Metro is the name for the systems in Paris and Washington, D.C. London’s system is often called the Tube.