[L. tubus.] A pipe; a siphon; a canal or conduit; a hollow cylinder, either of wood, metal or glass, used for the conveyance of fluids, and for various other purposes.

1. A vessel of animal bodies or plants, which conveys a fluid or other substance.

2. In botany, the narrow hollow part of a monopetalous corol, by which it is fixed to the receptacle.

3. In artillery, an instrument of tin, used in quick firing.