"off-metal" meaning in English

{
  "forms": [
    {
      "form": "off-metals",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "off-metal (plural off-metals)",
      "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"
        }
      ],
      "examples": [
        {
          "ref": "1971, Grover C. Criswell, The Official Guide to Confederate Money & Civil War Tokens, Tradesmen & Patriotic, page 121:",
          "text": "Most patriotics in copper or brass are common. They are rare in off-metals.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A coin or token struck in an abnormal choice of metal."
      ],
      "id": "en-off-metal-en-noun-RSvbv~C9",
      "links": [
        [
          "coin",
          "coin"
        ],
        [
          "token",
          "token"
        ],
        [
          "struck",
          "struck"
        ],
        [
          "abnormal",
          "abnormal"
        ],
        [
          "metal",
          "metal"
        ]
      ],
      "related": [
        {
          "word": "planchet"
        }
      ]
    }
  ],
  "word": "off-metal"
}

{
  "forms": [
    {
      "form": "off-metals",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "off-metal (plural off-metals)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "planchet"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "1971, Grover C. Criswell, The Official Guide to Confederate Money & Civil War Tokens, Tradesmen & Patriotic, page 121:",
          "text": "Most patriotics in copper or brass are common. They are rare in off-metals.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A coin or token struck in an abnormal choice of metal."
      ],
      "links": [
        [
          "coin",
          "coin"
        ],
        [
          "token",
          "token"
        ],
        [
          "struck",
          "struck"
        ],
        [
          "abnormal",
          "abnormal"
        ],
        [
          "metal",
          "metal"
        ]
      ]
    }
  ],
  "word": "off-metal"
}