"loop line" meaning in English

{
  "forms": [
    {
      "form": "loop lines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "loop line (plural loop lines)",
      "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"
        }
      ],
      "glosses": [
        "A secondary route which leaves a mainline, following a different route to the main line, before rejoining it several miles further on."
      ],
      "id": "en-loop_line-en-noun-DKhUYH1t",
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "mainline",
          "mainline"
        ]
      ],
      "raw_glosses": [
        "(rail transport) A secondary route which leaves a mainline, following a different route to the main line, before rejoining it several miles further on."
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    },
    {
      "categories": [
        {
          "_dis": "26 74",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "23 77",
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w+disamb"
        },
        {
          "_dis": "20 80",
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "A secondary route which forms a loop between two main lines, so that trains using it return to the same place."
      ],
      "id": "en-loop_line-en-noun-WqBlEaXT"
    }
  ],
  "synonyms": [
    {
      "_dis1": "46 54",
      "word": "loopline"
    }
  ],
  "word": "loop line"
}

{
  "categories": [
    "English countable nouns",
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English nouns",
    "Pages with 1 entry",
    "Pages with entries"
  ],
  "forms": [
    {
      "form": "loop lines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "loop line (plural loop lines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "en:Rail transportation"
      ],
      "glosses": [
        "A secondary route which leaves a mainline, following a different route to the main line, before rejoining it several miles further on."
      ],
      "links": [
        [
          "rail transport",
          "rail transport"
        ],
        [
          "mainline",
          "mainline"
        ]
      ],
      "raw_glosses": [
        "(rail transport) A secondary route which leaves a mainline, following a different route to the main line, before rejoining it several miles further on."
      ],
      "topics": [
        "rail-transport",
        "railways",
        "transport"
      ]
    },
    {
      "glosses": [
        "A secondary route which forms a loop between two main lines, so that trains using it return to the same place."
      ]
    }
  ],
  "synonyms": [
    {
      "word": "loopline"
    }
  ],
  "word": "loop line"
}