"back gray" meaning in English

{
  "forms": [
    {
      "form": "back grays",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "back gray (plural back grays)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "American English",
          "parents": [],
          "source": "w"
        },
        {
          "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": "Printing",
          "orig": "en:Printing",
          "parents": [
            "Industries",
            "Business",
            "Economics",
            "Society",
            "Social sciences",
            "All topics",
            "Sciences",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Textiles",
          "orig": "en:Textiles",
          "parents": [
            "Materials",
            "Manufacturing",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A piece of dark, heavy cotton cloth that is run under another piece of cloth to be printed, serving to take up the color on the roller outside the width of the print cloth."
      ],
      "id": "en-back_gray-en-noun-wnWPYo-4",
      "links": [
        [
          "printing",
          "printing#Noun"
        ],
        [
          "textiles",
          "textiles"
        ],
        [
          "cotton",
          "cotton"
        ],
        [
          "cloth",
          "cloth"
        ],
        [
          "roller",
          "roller"
        ]
      ],
      "raw_glosses": [
        "(US, printing, textiles, historical) A piece of dark, heavy cotton cloth that is run under another piece of cloth to be printed, serving to take up the color on the roller outside the width of the print cloth."
      ],
      "tags": [
        "US",
        "historical"
      ],
      "topics": [
        "business",
        "manufacturing",
        "media",
        "printing",
        "publishing",
        "textiles"
      ]
    }
  ],
  "word": "back gray"
}

{
  "forms": [
    {
      "form": "back grays",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "back gray (plural back grays)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "American English",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with historical senses",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Printing",
        "en:Textiles"
      ],
      "glosses": [
        "A piece of dark, heavy cotton cloth that is run under another piece of cloth to be printed, serving to take up the color on the roller outside the width of the print cloth."
      ],
      "links": [
        [
          "printing",
          "printing#Noun"
        ],
        [
          "textiles",
          "textiles"
        ],
        [
          "cotton",
          "cotton"
        ],
        [
          "cloth",
          "cloth"
        ],
        [
          "roller",
          "roller"
        ]
      ],
      "raw_glosses": [
        "(US, printing, textiles, historical) A piece of dark, heavy cotton cloth that is run under another piece of cloth to be printed, serving to take up the color on the roller outside the width of the print cloth."
      ],
      "tags": [
        "US",
        "historical"
      ],
      "topics": [
        "business",
        "manufacturing",
        "media",
        "printing",
        "publishing",
        "textiles"
      ]
    }
  ],
  "word": "back gray"
}