Main entry: metro, tube, underground, subway, subway system
Definition: an electric railway operating below the surface of the ground (usually in a city)
Usage: in Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'
Definition: conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
Main entry: tube, thermionic tube, thermionic vacuum tube, thermionic valve, vacuum tube, electron tube
Definition: electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope
Main entry: tube, tube-shaped structure
Definition: (anatomy) any hollow cylindrical body structure
Definition: a hollow cylindrical shape
Main entry: tube
Definition: place or enclose in a tube
Main entry: tube
Definition: ride or float on an inflated tube
Usage: We tubed down the river on a hot summer day
Main entry: tube
Definition: convey in a tube
Usage: inside Paris, they used to tube mail
Main entry: tube
Definition: provide with a tube or insert a tube into