"underground railway" meaning in English

{
  "forms": [
    {
      "form": "underground railways",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "underground railway (plural underground railways)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Rail transportation",
          "orig": "en:Rail transportation",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "english": "as subway",
          "tags": [
            "noun"
          ],
          "word": "underground"
        }
      ],
      "examples": [
        {
          "ref": "2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 29",
          "text": "It was advisable to avoid building an underground railway beneath private houses at the time, because the law would require you to buy those houses.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Synonym of subway: a railway under the ground."
      ],
      "id": "en-underground_railway-en-noun-jAt7YqQd",
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "subway",
          "subway#English"
        ],
        [
          "railway",
          "railway"
        ],
        [
          "ground",
          "ground"
        ]
      ],
      "raw_glosses": [
        "(rail transport) Synonym of subway: a railway under the ground."
      ],
      "synonyms": [
        {
          "extra": "a railway under the ground",
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "subway"
        }
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    }
  ],
  "word": "underground railway"
}

{
  "head_templates": [
    {
      "args": {},
      "expansion": "underground railway",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "alt_of": [
        {
          "word": "Underground Railroad"
        }
      ],
      "categories": [
        {
          "_dis": "91 9",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Alternative form of Underground Railroad"
      ],
      "id": "en-underground_railway-en-name-G3U~VyMK",
      "links": [
        [
          "capitalized",
          "capitalisation"
        ],
        [
          "Underground Railroad",
          "Underground Railroad#English"
        ]
      ],
      "raw_glosses": [
        "(usually capitalized) Alternative form of Underground Railroad"
      ],
      "related": [
        {
          "word": "underground railroad"
        }
      ],
      "tags": [
        "alt-of",
        "alternative",
        "capitalized",
        "usually"
      ]
    }
  ],
  "word": "underground railway"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns",
    "English proper nouns",
    "English uncountable nouns"
  ],
  "derived": [
    {
      "english": "as subway",
      "tags": [
        "noun"
      ],
      "word": "underground"
    }
  ],
  "forms": [
    {
      "form": "underground railways",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "underground railway (plural underground railways)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English terms with quotations",
        "en:Rail transportation"
      ],
      "examples": [
        {
          "ref": "2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 29",
          "text": "It was advisable to avoid building an underground railway beneath private houses at the time, because the law would require you to buy those houses.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Synonym of subway: a railway under the ground."
      ],
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "subway",
          "subway#English"
        ],
        [
          "railway",
          "railway"
        ],
        [
          "ground",
          "ground"
        ]
      ],
      "raw_glosses": [
        "(rail transport) Synonym of subway: a railway under the ground."
      ],
      "synonyms": [
        {
          "extra": "a railway under the ground",
          "tags": [
            "synonym",
            "synonym-of"
          ],
          "word": "subway"
        }
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    }
  ],
  "word": "underground railway"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns",
    "English proper nouns",
    "English uncountable nouns"
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "underground railway",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "related": [
    {
      "word": "underground railroad"
    }
  ],
  "senses": [
    {
      "alt_of": [
        {
          "word": "Underground Railroad"
        }
      ],
      "glosses": [
        "Alternative form of Underground Railroad"
      ],
      "links": [
        [
          "capitalized",
          "capitalisation"
        ],
        [
          "Underground Railroad",
          "Underground Railroad#English"
        ]
      ],
      "raw_glosses": [
        "(usually capitalized) Alternative form of Underground Railroad"
      ],
      "tags": [
        "alt-of",
        "alternative",
        "capitalized",
        "usually"
      ]
    }
  ],
  "word": "underground railway"
}