Noun Concept
Categories: 1863 introductions, Passenger rail transport, All articles containing potentially dated statements, Rapid transit
rapid transit  mass rapid transit  underground train
Rapid transit or mass rapid transit, also known as heavy rail, metro, subway, tube, U-Bahn, metropolitana or underground, is a type of high-capacity public transport generally found in urban areas. Wikipedia
Type of fully grade-separated passenger railway system commonly found in urban areas Wikidata
A train for transportation of people, mostly beneath the surface of the ground, in order to lessen the traffic. OmegaWiki
A commuter rail system that combines aspects of an interurban railway with those of a subway, using a menagerie of pathways such as viaduct, tunnel, beam, cut and cover, trench, at grade, and others. Wiktionary
Commuter rail system. Wiktionary (translation)