WordWeb Online

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'";
   - tube [UK], underground [Brit], subway system [N. Amer], subway [N. Amer]

Derived forms: metros

Type of: rail, railroad [N. Amer], railroad line [N. Amer], railway [Brit, Cdn], railway line [Brit, Cdn], railway system [Brit, Cdn]

Encyclopedia: Metro, Peter