"motley iron" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "motley iron (uncountable)",
      "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"
        }
      ],
      "glosses": [
        "A medium-quality cast iron, consisting of a mixture of white iron and grey iron."
      ],
      "id": "en-motley_iron-en-noun-ZQwz0JUd",
      "links": [
        [
          "cast iron",
          "cast iron"
        ],
        [
          "white iron",
          "white iron"
        ],
        [
          "grey iron",
          "grey iron"
        ]
      ],
      "raw_glosses": [
        "(obsolete) A medium-quality cast iron, consisting of a mixture of white iron and grey iron."
      ],
      "tags": [
        "obsolete",
        "uncountable"
      ]
    }
  ],
  "word": "motley iron"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "motley iron (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with obsolete senses",
        "English uncountable nouns"
      ],
      "glosses": [
        "A medium-quality cast iron, consisting of a mixture of white iron and grey iron."
      ],
      "links": [
        [
          "cast iron",
          "cast iron"
        ],
        [
          "white iron",
          "white iron"
        ],
        [
          "grey iron",
          "grey iron"
        ]
      ],
      "raw_glosses": [
        "(obsolete) A medium-quality cast iron, consisting of a mixture of white iron and grey iron."
      ],
      "tags": [
        "obsolete",
        "uncountable"
      ]
    }
  ],
  "word": "motley iron"
}