Definition of: tube

(tb, tyb) noun
1. A long hollow cylindrical body of metal, glass, rubber, etc., generally used for the conveyance of something through it; a pipe.
2. The principal part of a gun.
3. Any similar device having a tube or tubelike part, as a telescope.
4. Biol. Any elongated hollow part or organ, as the united part of a gamopetalous corolla or a gamosepalous calyx.
5. A subway or a tunnel.
6. An electron, thermionic, or vacuum tube.
7. The tubular space enclosing lines of magnetic force or induction.
8. A collapsible metal cylinder for containing paints, toothpaste, glue, and the like.
—v.t. tubed, tub·ing
1. To fit or furnish with a tube.
2. To enclose in a tube or tubes.
3. To make tubular. [<F <L tubus a tube]
—tube′less adjective
—tub′er noun
Tube may appear as a combining form in hyphemes or solidemes, with the meaning of noun definition 1: