"dark ages" meaning in English

{
  "forms": [
    {
      "form": "the dark ages",
      "tags": [
        "canonical",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "p",
        "def": "1"
      },
      "expansion": "the dark ages pl (plural only)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "Dark Ages"
        }
      ],
      "categories": [
        {
          "_dis": "98 2",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        },
        {
          "_dis": "76 24",
          "kind": "other",
          "name": "English pluralia tantum",
          "parents": [
            "Pluralia tantum",
            "Nouns",
            "Lemmas"
          ],
          "source": "w+disamb"
        }
      ],
      "glosses": [
        "Alternative letter-case form of Dark Ages"
      ],
      "id": "en-dark_ages-en-noun-jatb9JcN",
      "links": [
        [
          "Dark Ages",
          "Dark Ages#English"
        ]
      ],
      "tags": [
        "alt-of",
        "plural",
        "plural-only"
      ]
    }
  ],
  "word": "dark ages"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun form"
      },
      "expansion": "dark ages",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "form_of": [
        {
          "word": "dark age"
        }
      ],
      "glosses": [
        "plural of dark age"
      ],
      "id": "en-dark_ages-en-noun-CRiW4xhm",
      "links": [
        [
          "dark age",
          "dark age#English"
        ]
      ],
      "tags": [
        "form-of",
        "plural"
      ]
    }
  ],
  "word": "dark ages"
}

{
  "categories": [
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English non-lemma forms",
    "English noun forms",
    "English nouns",
    "English pluralia tantum"
  ],
  "forms": [
    {
      "form": "the dark ages",
      "tags": [
        "canonical",
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "p",
        "def": "1"
      },
      "expansion": "the dark ages pl (plural only)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "Dark Ages"
        }
      ],
      "glosses": [
        "Alternative letter-case form of Dark Ages"
      ],
      "links": [
        [
          "Dark Ages",
          "Dark Ages#English"
        ]
      ],
      "tags": [
        "alt-of",
        "plural",
        "plural-only"
      ]
    }
  ],
  "word": "dark ages"
}

{
  "categories": [
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English non-lemma forms",
    "English noun forms",
    "English nouns",
    "English pluralia tantum"
  ],
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "noun form"
      },
      "expansion": "dark ages",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "form_of": [
        {
          "word": "dark age"
        }
      ],
      "glosses": [
        "plural of dark age"
      ],
      "links": [
        [
          "dark age",
          "dark age#English"
        ]
      ],
      "tags": [
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        "plural"
      ]
    }
  ],
  "word": "dark ages"
}