"2-8-8-2" meaning in English

{
  "forms": [
    {
      "form": "2-8-8-2s",
      "tags": [
        "plural"
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    }
  ],
  "head_templates": [
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      "args": {},
      "expansion": "2-8-8-2 (plural 2-8-8-2s)",
      "name": "en-noun"
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
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        {
          "kind": "topical",
          "langcode": "en",
          "name": "Rail transportation",
          "orig": "en:Rail transportation",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
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          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              43,
              50
            ]
          ],
          "ref": "1961 July 12, J. Geoffrey Todd, “Impressions of railroading in the United States: Part Two”, in Trains Illustrated, page 419:",
          "text": "The leading engine was one of the Class Y6 2-8-8-2 compound articulateds, […] The stack noise of one of these great brutes slogging up a grade was quite unforgettable.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Under the Whyte notation system, a Mallet-type locomotive with two leading wheels on a leading truck, two sets of eight driving wheels, and two trailing wheels on a trailing truck."
      ],
      "id": "en-2-8-8-2-en-noun-xLFAcKAZ",
      "links": [
        [
          "Mallet",
          "Mallet"
        ],
        [
          "locomotive",
          "locomotive"
        ],
        [
          "leading wheel",
          "leading wheel"
        ],
        [
          "leading truck",
          "leading truck"
        ],
        [
          "driving wheel",
          "driving wheel"
        ],
        [
          "trailing wheel",
          "trailing wheel"
        ],
        [
          "trailing truck",
          "trailing truck"
        ]
      ]
    }
  ],
  "word": "2-8-8-2"
}

{
  "forms": [
    {
      "form": "2-8-8-2s",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
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      "expansion": "2-8-8-2 (plural 2-8-8-2s)",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
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        "en:Rail transportation"
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          ],
          "ref": "1961 July 12, J. Geoffrey Todd, “Impressions of railroading in the United States: Part Two”, in Trains Illustrated, page 419:",
          "text": "The leading engine was one of the Class Y6 2-8-8-2 compound articulateds, […] The stack noise of one of these great brutes slogging up a grade was quite unforgettable.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Under the Whyte notation system, a Mallet-type locomotive with two leading wheels on a leading truck, two sets of eight driving wheels, and two trailing wheels on a trailing truck."
      ],
      "links": [
        [
          "Mallet",
          "Mallet"
        ],
        [
          "locomotive",
          "locomotive"
        ],
        [
          "leading wheel",
          "leading wheel"
        ],
        [
          "leading truck",
          "leading truck"
        ],
        [
          "driving wheel",
          "driving wheel"
        ],
        [
          "trailing wheel",
          "trailing wheel"
        ],
        [
          "trailing truck",
          "trailing truck"
        ]
      ]
    }
  ],
  "word": "2-8-8-2"
}