English to English

noun (n)

• an electric railway operating below the surface of the ground (usually in a city)

  kereta api listrik beroperasi di bawah permukaan tanah (biasanya dalam bandar)

  Example:
  In Paris the subway system is called the `metro' and in London it is called the `tube' or the `underground'.
  

  Synonym:
  subway, subway system, tube, underground
  

  source: wordnet30