"2-12-4" meaning in All languages combined

{
  "forms": [
    {
      "form": "2-12-4s",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "2-12-4 (plural 2-12-4s)",
      "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"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Rail transportation",
          "orig": "en:Rail transportation",
          "parents": [
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Under the Whyte notation system, a steam locomotive that has two leading wheels, six pairs of coupled driving wheels, and four trailing wheels."
      ],
      "id": "en-2-12-4-en-noun-Y~kihvWT",
      "links": [
        [
          "steam locomotive",
          "steam locomotive"
        ],
        [
          "leading wheel",
          "leading wheel"
        ],
        [
          "driving wheel",
          "driving wheel"
        ],
        [
          "trailing wheel",
          "trailing wheel"
        ]
      ],
      "wikipedia": [
        "2-12-4"
      ]
    }
  ],
  "word": "2-12-4"
}

{
  "forms": [
    {
      "form": "2-12-4s",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "2-12-4 (plural 2-12-4s)",
      "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 spelled with numbers",
        "English words without vowels",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Rail transportation"
      ],
      "glosses": [
        "Under the Whyte notation system, a steam locomotive that has two leading wheels, six pairs of coupled driving wheels, and four trailing wheels."
      ],
      "links": [
        [
          "steam locomotive",
          "steam locomotive"
        ],
        [
          "leading wheel",
          "leading wheel"
        ],
        [
          "driving wheel",
          "driving wheel"
        ],
        [
          "trailing wheel",
          "trailing wheel"
        ]
      ],
      "wikipedia": [
        "2-12-4"
      ]
    }
  ],
  "word": "2-12-4"
}