tube

(to͞ob, tyo͞ob)

1. a. A hollow cylinder, especially one that conveys a fluid or functions as a passage.
   b. An organic structure having the shape or function of a tube; a duct: a bronchial tube.
2. A small flexible cylindrical container sealed at one end and having a screw cap at the other, for pigments, toothpaste, or other pastelike substances.
3. Music The cylindrical part of a wind instrument.
4. Electronics
   a. An electron tube.
   b. A vacuum tube.
5. Botany The lower, cylindrical part of a gamopetalous corolla or a gamosepalous calyx.
6. Chiefly British
   a. An underground railroad tunnel.
   b. An underground railroad system, especially the one in London, England.
7. A tunnel.
8. a. An inner tube.
   b. An inflatable tube or cushion made of rubber or plastic and used for recreational riding, as behind a motor boat or down a snow-covered slope.
9. Informal
   a. Television: What's on the tube?
   b. A television set.
10. tubes Informal The fallopian tubes.

1. To provide with a tube; insert a tube in.
2. To place in or enclose in a tube.