- The Washington, DC Metro is an example of a subway.
- The tunnel that a New York City train runs through is an example of a subway.
The definition of a subway is an underground train system, or an underground passage.
- an underground way or passage
- Chiefly Brit. an underpass for pedestrians
- an underground, metropolitan electric railway or the tunnel through which it runs
- a. An underground urban railroad, usually operated by electricity.b. A passage for such a railroad.
- An underground tunnel or passage, as for a water main or for pedestrians.
(third-person singular simple present subways, present participle subwaying, simple past and past participle subwayed)
- (intransitive, US, informal) To travel by underground railway.
sub- (“under") + way