metro

The word "metro" usually brings to mind life in a big city: stations below the street, trains arriving every few minutes, and people moving quickly from one part of town to another. Most often, "metro" means a city's rapid transit railway system, like the Paris Metro or the Washington Metro.

In some contexts, "metro" also relates to the larger city area, especially in phrases like "metro area." In that sense, it means the main city together with the nearby suburbs and towns that are closely connected to it.

"Metro" comes from "metropolitan," so it is closely tied to big cities. Its most common meaning is a *subway or urban rail system* that carries people around a city. When someone says, "I took the metro," they usually mean they traveled by an underground or city train system. In many parts of the world, this is the normal everyday meaning of the word.

"Metro" can also appear in names and descriptions connected with a major city. A phrase like *metro area* means the main city plus the nearby suburbs and towns that form one connected urban region. You may also see the word in the names of transport systems, agencies, newspapers, or services that serve a metropolitan area.

So the word has two main ideas that stay close to each other: the *city rail network itself, and the larger urban area* around a major city. Whether you are talking about catching a train downtown or describing the wider region around a capital, "metro" points back to the life and structure of a big city.