Definitions:

1. an electric railway operating below the surface of the ground, usually in a city noun
   • In Paris, the underground system of trains is known as the metro.

Synonyms:

• underground

NearBy Words:

• metrological
• metrology
• metronidazole
• metronome
• metronymic
• metropolis
• metropolitan
• metroptosis
• metrorrhagia
• metrosexual
• metroxylon