"coalblack" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "coal",
        "3": "black"
      },
      "expansion": "coal + black",
      "name": "compound"
    }
  ],
  "etymology_text": "From coal + black. From black as coal.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "coalblack (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "coal black"
        }
      ],
      "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"
        }
      ],
      "glosses": [
        "Alternative form of coal black"
      ],
      "id": "en-coalblack-en-adj-~YMQ2WCY",
      "links": [
        [
          "coal black",
          "coal black#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "not-comparable"
      ]
    }
  ],
  "word": "coalblack"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "coal",
        "3": "black"
      },
      "expansion": "coal + black",
      "name": "compound"
    }
  ],
  "etymology_text": "From coal + black. From black as coal.",
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "coalblack (not comparable)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "alt_of": [
        {
          "word": "coal black"
        }
      ],
      "categories": [
        "English adjectives",
        "English compound terms",
        "English entries with incorrect language header",
        "English lemmas",
        "English uncomparable adjectives",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "Alternative form of coal black"
      ],
      "links": [
        [
          "coal black",
          "coal black#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "not-comparable"
      ]
    }
  ],
  "word": "coalblack"
}