the tube

WordReference Random House Learner's Dictionary of American English © 2026

tube /tub, tyub/   n., v., tubed, tub•ing. 
n. [countable]

1. a hollow, rounded, narrow piece of metal, glass, etc., used esp. for carrying liquids or gases:
   a short rubber tube.
2. a small collapsible cylinder sealed at one end, with a capped opening at the other end, from which a substance, as toothpaste, may be squeezed.
3. Anatomy, Zoology any hollow, rounded, narrow vessel or organ in the body:
   the bronchial tubes.
4. Electronics electron tube.
5. Informal Terms the tube, [singular] television:
   What's on the tube tonight?
6. Clothing a rounded, narrow piece of clothing without sleeves, pockets, or closures, usually of stretch fabric, worn as a blouse, skirt, etc.
7. Transport the tunnel in which an underground railroad runs.
8. British Terms subway (def. 1).

v. [no object]

9. to float down a river on an inner tube.

Idioms

10. Idioms down the tube(s), into a state of failure or collapse:
    All his efforts went down the tube when the company went bankrupt.

tube•less, adj. 

WordReference Random House Unabridged Dictionary of American English © 2026

tube  (to̅o̅b, tyo̅o̅b), n., v., tubed, tub•ing. 
n. 

1. a hollow, usually cylindrical body of metal, glass, rubber, or other material, used esp. for conveying or containing liquids or gases.
2. a small, collapsible, cylinder of metal or plastic sealed at one end and having a capped opening at the other from which paint, toothpaste, or some other semifluid substance may be squeezed.
3. Anatomy, Zoology any hollow, cylindrical vessel or organ:
   the bronchial tubes.
4. [Bot.]
   • Botany any hollow, elongated body or part.
   • Botany the united lower portion of a gamopetalous corolla or a gamosepalous calyx.
5. See inner tube. 
6. Electronics See electron tube. 
7. Informal Terms
   • television.
   • a television set.
8. See mailing tube. 
9. Transport the tubular tunnel in which an underground railroad runs.
10. Transport the railroad itself.
11. Sport [Surfing Slang.] the curled hollow formed on the underside of a cresting wave.
12. British Terms subway (def. 1).
13. British Terms [Australian Slang.] a can of beer.
14. Optics, Slang Terms [Older Slang.] a telescope.
15. down the tube or tubes, [Informal.] into a ruined, wasted, or abandoned state or condition.

v.t. 

16. to furnish with a tube or tubes.
17. to convey or enclose in a tube.
18. to form into the shape of a tube;
    make tubular.

• Latin tubus pipe
• 1590–1600

tube′less, adj. 
tube′like′, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::

tube / tjuːb/ noun

1. a long hollow and typically cylindrical object, used for the passage of fluids or as a container
2. a collapsible cylindrical container of soft metal or plastic closed with a cap, used to hold viscous liquids or pastes
3. short for Eustachian tube, Fallopian tube
4. any hollow cylindrical structure
5. any other hollow structure in a plant
6. the tube ⇒
   Also called: the underground an underground railway system
   US and Canadian equivalent: subway
7. the tunnels through which the railway runs
8. another name for valve3
9. See electron tube, cathode-ray tube, television tube
10. the tube ⇒ a television set
11. a foolish or despicable person
12. a bottle or can of beer
13. the cylindrical passage formed when a wave breaks and the crest tips forward
14. an archaic word for telescope

verb (transitive)

1. to fit or supply with a tube or tubes
2. to carry or convey in a tube
3. to shape like a tube

Etymology: 17th Century: from Latin tubus

ˈtubeless adjective