1.conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
2.electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
3.a hollow cylindrical shape
4.(anatomy) any hollow cylindrical body structure
5.electric underground railway
1.provide with a tube or insert a tube into
2.convey in a tube;
inside Paris, they used to tube mail
3.ride or float on an inflated tube;
We tubed down the river on a hot summer day
4.place or enclose in a tube