"dark nebula" meaning in English

{
  "forms": [
    {
      "form": "dark nebulas",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "dark nebulae",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "s",
        "2": "dark nebulae"
      },
      "expansion": "dark nebula (plural dark nebulas or dark nebulae)",
      "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"
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          "source": "w"
        },
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          "parents": [],
          "source": "w"
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        {
          "kind": "other",
          "name": "Terms with Japanese translations",
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Russian translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Astronomy",
          "orig": "en:Astronomy",
          "parents": [
            "Sciences",
            "Space",
            "All topics",
            "Nature",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "The Horsehead Nebula is a typical dark nebula, and is famous for resembling the head of a horse.",
          "type": "example"
        }
      ],
      "glosses": [
        "A type of nebula that does not emit or reflect (visible) light, and thus obscures light sources behind it."
      ],
      "id": "en-dark_nebula-en-noun-X5WqsGcq",
      "links": [
        [
          "astronomy",
          "astronomy"
        ],
        [
          "nebula",
          "nebula"
        ]
      ],
      "raw_glosses": [
        "(astronomy) A type of nebula that does not emit or reflect (visible) light, and thus obscures light sources behind it."
      ],
      "related": [
        {
          "word": "emission nebula"
        },
        {
          "word": "reflection nebula"
        }
      ],
      "synonyms": [
        {
          "word": "dark cloud"
        }
      ],
      "topics": [
        "astronomy",
        "natural-sciences"
      ],
      "translations": [
        {
          "code": "hy",
          "lang": "Armenian",
          "roman": "mutʻ migamacutʻyun",
          "sense": "type of nebula",
          "word": "մութ միգամածություն"
        },
        {
          "code": "ja",
          "lang": "Japanese",
          "roman": "ankoku seiun",
          "sense": "type of nebula",
          "word": "暗黒星雲"
        },
        {
          "code": "ru",
          "lang": "Russian",
          "roman": "tjómnaja tumánnostʹ",
          "sense": "type of nebula",
          "tags": [
            "feminine"
          ],
          "word": "тёмная тума́нность"
        }
      ],
      "wikipedia": [
        "dark nebula"
      ]
    }
  ],
  "word": "dark nebula"
}

{
  "forms": [
    {
      "form": "dark nebulas",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "dark nebulae",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "s",
        "2": "dark nebulae"
      },
      "expansion": "dark nebula (plural dark nebulas or dark nebulae)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "emission nebula"
    },
    {
      "word": "reflection nebula"
    }
  ],
  "senses": [
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      ],
      "examples": [
        {
          "text": "The Horsehead Nebula is a typical dark nebula, and is famous for resembling the head of a horse.",
          "type": "example"
        }
      ],
      "glosses": [
        "A type of nebula that does not emit or reflect (visible) light, and thus obscures light sources behind it."
      ],
      "links": [
        [
          "astronomy",
          "astronomy"
        ],
        [
          "nebula",
          "nebula"
        ]
      ],
      "raw_glosses": [
        "(astronomy) A type of nebula that does not emit or reflect (visible) light, and thus obscures light sources behind it."
      ],
      "synonyms": [
        {
          "word": "dark cloud"
        }
      ],
      "topics": [
        "astronomy",
        "natural-sciences"
      ],
      "wikipedia": [
        "dark nebula"
      ]
    }
  ],
  "translations": [
    {
      "code": "hy",
      "lang": "Armenian",
      "roman": "mutʻ migamacutʻyun",
      "sense": "type of nebula",
      "word": "մութ միգամածություն"
    },
    {
      "code": "ja",
      "lang": "Japanese",
      "roman": "ankoku seiun",
      "sense": "type of nebula",
      "word": "暗黒星雲"
    },
    {
      "code": "ru",
      "lang": "Russian",
      "roman": "tjómnaja tumánnostʹ",
      "sense": "type of nebula",
      "tags": [
        "feminine"
      ],
      "word": "тёмная тума́нность"
    }
  ],
  "word": "dark nebula"
}