"unslack" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "un",
        "3": "slack"
      },
      "expansion": "un- + slack",
      "name": "pre"
    }
  ],
  "etymology_text": "From un- + slack.",
  "forms": [
    {
      "form": "more unslack",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most unslack",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unslack (comparative more unslack, superlative most unslack)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with un-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              31,
              38
            ]
          ],
          "ref": "1961, American Institute of Mining, Metallurgical, and Petroleum Engineers, Papers and Discussions Presented Before the [Coal] Division, page 440:",
          "text": "[…] and only 27 percent of the unslack sample planes were clay.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Not slack."
      ],
      "id": "en-unslack-en-adj-vxPC5OCc",
      "links": [
        [
          "slack",
          "slack"
        ]
      ],
      "raw_glosses": [
        "(rare) Not slack."
      ],
      "tags": [
        "rare"
      ]
    }
  ],
  "word": "unslack"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "un",
        "3": "slack"
      },
      "expansion": "un- + slack",
      "name": "pre"
    }
  ],
  "etymology_text": "From un- + slack.",
  "forms": [
    {
      "form": "more unslack",
      "tags": [
        "comparative"
      ]
    },
    {
      "form": "most unslack",
      "tags": [
        "superlative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "unslack (comparative more unslack, superlative most unslack)",
      "name": "en-adj"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "English adjectives",
        "English entries with incorrect language header",
        "English lemmas",
        "English terms prefixed with un-",
        "English terms with quotations",
        "English terms with rare senses",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              31,
              38
            ]
          ],
          "ref": "1961, American Institute of Mining, Metallurgical, and Petroleum Engineers, Papers and Discussions Presented Before the [Coal] Division, page 440:",
          "text": "[…] and only 27 percent of the unslack sample planes were clay.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Not slack."
      ],
      "links": [
        [
          "slack",
          "slack"
        ]
      ],
      "raw_glosses": [
        "(rare) Not slack."
      ],
      "tags": [
        "rare"
      ]
    }
  ],
  "word": "unslack"
}