1. an underground railway system in a city
Usage: chiefly US
2. an underground passage for pedestrians

Examples

• I take the subway to work every morning.
• The subway station is just two blocks away.
• New York’s subway system operates 24 hours a day.
• She got lost in the subway tunnels.
• We used the subway to cross under the busy street.
• The subway was crowded during rush hour.
• Construction workers are building a new subway line.