"cat train" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "cat",
        "3": "train"
      },
      "expansion": "cat + train",
      "name": "compound"
    }
  ],
  "etymology_text": "From cat + train. From having a caterpillar-drive tractor unit pulling a train of cargo.",
  "forms": [
    {
      "form": "cat trains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "cat train (plural cat trains)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
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          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "An off-road frozen-surface cargo train pulled by a cat (caterpillar-drive truck) with a trail of ski trailers and sledges"
      ],
      "id": "en-cat_train-en-noun-JEHivPjF",
      "related": [
        {
          "word": "snowcat"
        },
        {
          "word": "cat skiing"
        }
      ]
    }
  ],
  "word": "cat train"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "cat",
        "3": "train"
      },
      "expansion": "cat + train",
      "name": "compound"
    }
  ],
  "etymology_text": "From cat + train. From having a caterpillar-drive tractor unit pulling a train of cargo.",
  "forms": [
    {
      "form": "cat trains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "cat train (plural cat trains)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "snowcat"
    },
    {
      "word": "cat skiing"
    }
  ],
  "senses": [
    {
      "categories": [
        "English compound terms",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "An off-road frozen-surface cargo train pulled by a cat (caterpillar-drive truck) with a trail of ski trailers and sledges"
      ]
    }
  ],
  "word": "cat train"
}