(noun, verb)


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'

Similar word(s): metro, tube, underground

Definition categories: man–made, railroad, railway

2. an underground tunnel or passage enabling pedestrians to cross a road or railway

Similar word(s): underpass

Definition categories: man–made, tunnel


1. (intransitive, US, informal) To travel by underground railway.