—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. Anat.,Zool.any hollow, cylindrical vessel or organ: the bronchial tubes. 4. Bot. a. any hollow, elongated body or part.
b. the united lower portion of a gamopetalous corolla or a gamosepalous calyx.
5. See inner tube. 6. Electronics.See electron tube. 7. Informal. a. television.
b. a television set.
8. See mailing tube. 9. the tubular tunnel in which an underground railroad runs.
10. the railroad itself.
11. Surfing Slang.the curled hollow formed on the underside of a cresting wave.
12. Brit.subway (def. 1).
13. Australian Slang.a can of beer.
14. Older Slang.a telescope.
15. down the tube or tubes,Informal.into a ruined, wasted, or abandoned state or condition.
—v.t. 1. to furnish with a tube or tubes.
2. to convey or enclose in a tube.
3. to form into the shape of a tube; make tubular.