"patent fuel" meaning in English

{
  "forms": [
    {
      "form": "patent fuels",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "patent fuel (countable and uncountable, plural patent fuels)",
      "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"
        }
      ],
      "examples": [
        {
          "ref": "1959 May, R. A. Savill, “The coal traffic of the North Eastern Region”, in Trains Illustrated, page 272",
          "text": "The originating tonnage of coal class traffic (that is to say coal, coke and patent fuel) for the whole of British Railways in 1957 was 166,153,300 tons, representing half-a-million tons a day and roughly 60 per cent of the total freight traffic.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Fuel, usually in the form of briquettes, made from fine, crushed coal with the addition of a binding agent."
      ],
      "id": "en-patent_fuel-en-noun-YorbJhKg",
      "links": [
        [
          "briquette",
          "briquette"
        ],
        [
          "coal",
          "coal"
        ],
        [
          "binding agent",
          "binding agent"
        ]
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "patent fuel"
}

{
  "forms": [
    {
      "form": "patent fuels",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "patent fuel (countable and uncountable, plural patent fuels)",
      "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 with quotations",
        "English uncountable nouns"
      ],
      "examples": [
        {
          "ref": "1959 May, R. A. Savill, “The coal traffic of the North Eastern Region”, in Trains Illustrated, page 272",
          "text": "The originating tonnage of coal class traffic (that is to say coal, coke and patent fuel) for the whole of British Railways in 1957 was 166,153,300 tons, representing half-a-million tons a day and roughly 60 per cent of the total freight traffic.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Fuel, usually in the form of briquettes, made from fine, crushed coal with the addition of a binding agent."
      ],
      "links": [
        [
          "briquette",
          "briquette"
        ],
        [
          "coal",
          "coal"
        ],
        [
          "binding agent",
          "binding agent"
        ]
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "patent fuel"
}