"balloon loop" meaning in English

{
  "etymology_text": "From its typical shape.",
  "forms": [
    {
      "form": "balloon loops",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "balloon loop (plural balloon loops)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Balloon loops can be useful for passenger trains and unit freight trains, such as coal trains.",
          "type": "example"
        }
      ],
      "glosses": [
        "A looped section of track that allows a rail vehicle or train to reverse direction without having to shunt or even stop."
      ],
      "id": "en-balloon_loop-en-noun-HnYGjzNq",
      "links": [
        [
          "loop",
          "loop"
        ],
        [
          "track",
          "track"
        ],
        [
          "rail",
          "rail"
        ],
        [
          "vehicle",
          "vehicle"
        ],
        [
          "train",
          "train"
        ],
        [
          "reverse",
          "reverse"
        ],
        [
          "direction",
          "direction"
        ],
        [
          "shunt",
          "shunt"
        ]
      ],
      "synonyms": [
        {
          "word": "reversing loop"
        },
        {
          "word": "turning loop"
        }
      ],
      "wikipedia": [
        "balloon loop"
      ]
    }
  ],
  "word": "balloon loop"
}

{
  "etymology_text": "From its typical shape.",
  "forms": [
    {
      "form": "balloon loops",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "balloon loop (plural balloon loops)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with usage examples"
      ],
      "examples": [
        {
          "text": "Balloon loops can be useful for passenger trains and unit freight trains, such as coal trains.",
          "type": "example"
        }
      ],
      "glosses": [
        "A looped section of track that allows a rail vehicle or train to reverse direction without having to shunt or even stop."
      ],
      "links": [
        [
          "loop",
          "loop"
        ],
        [
          "track",
          "track"
        ],
        [
          "rail",
          "rail"
        ],
        [
          "vehicle",
          "vehicle"
        ],
        [
          "train",
          "train"
        ],
        [
          "reverse",
          "reverse"
        ],
        [
          "direction",
          "direction"
        ],
        [
          "shunt",
          "shunt"
        ]
      ],
      "wikipedia": [
        "balloon loop"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "reversing loop"
    },
    {
      "word": "turning loop"
    }
  ],
  "word": "balloon loop"
}