1. Conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects, liquids or gases
   "Water flowed through the copper tube";
   - tubing
    
2. Electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
   "Vintage audio enthusiasts prefer amplifiers with vacuum tubes for their warm sound";
   - vacuum tube, thermionic vacuum tube, thermionic tube, electron tube, thermionic valve
    
3. A hollow cylindrical shape
   "The scientist examined the sample through a glass tube";
   - pipe
    
4. (anatomy) any hollow cylindrical body structure
   "The oesophagus is a tube-shaped structure that connects the throat to the stomach";
   - tube-shaped structure
    
5. [UK] An electric railway operating below the surface of the ground (usually in a city)
   "We took the tube to avoid traffic congestion";
   - metro, underground [Brit], subway system [N. Amer], subway [N. Amer]

1. Provide with a tube or insert a tube into
   "The doctor tubed the patient to assist with breathing"
    
2. Convey in a tube
   "inside Paris, they used to tube mail"
    
3. Place or enclose in a tube
   "The lab technician tubed the blood samples for transport"
    
4. Ride or float on an inflated tube
   "We tubed down the river on a hot summer day"

Derived forms: tubing, tubed, tubes

Type of: anatomical structure, bodily structure, body structure, bring, complex body part, conduit, convey, cylinder, electronic device, enclose, enfold, envelop, enwrap, furnish, offer, provide, rail, railroad [N. Amer], railroad line [N. Amer], railway [Brit, Cdn], railway line [Brit, Cdn], railway system [Brit, Cdn], render, ride, structure, supply, take, wrap

Part of: circuit, electric circuit, electrical circuit

Encyclopedia: Tube