subway
US /ˈsʌb.weɪ/
UK /ˈsʌb.weɪ/

1.
an underground electric railway, especially in a city
:
•
I take the subway to work every day.
•
The subway system in New York is very extensive.
2.
an underground passage for pedestrians to cross a road or railway
:
•
Use the subway to cross the busy street safely.
•
There's a pedestrian subway near the station.