📖 WordNook

tube

noun
  1. an electric railway operating below the surface of the ground (usually in a city)
    “in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'”
    underground
  2. conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
    tubing
  3. electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
    thermionic vacuum tubethermionic tubeelectron tubethermionic valve
  4. (anatomy) any hollow cylindrical body structure
  5. a hollow cylindrical shape
    pipe
verb
  1. place or enclose in a tube
  2. ride or float on an inflated tube
    “We tubed down the river on a hot summer day”
  3. convey in a tube
    “inside Paris, they used to tube mail”
  4. provide with a tube or insert a tube into