"open cluster" meaning in English

{
  "forms": [
    {
      "form": "open clusters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "open cluster (plural open clusters)",
      "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"
          ],
          "source": "w"
        },
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          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
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        },
        {
          "kind": "other",
          "name": "Japanese terms with redundant script codes",
          "parents": [
            "Terms with redundant script codes",
            "Entry maintenance"
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          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
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        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Esperanto translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Finnish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with French translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Japanese translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Astronomy",
          "orig": "en:Astronomy",
          "parents": [
            "Sciences",
            "Space",
            "All topics",
            "Nature",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "a more or less irregular star cluster containing tens to thousands of stars"
      ],
      "id": "en-open_cluster-en-noun-djhauaWE",
      "links": [
        [
          "astronomy",
          "astronomy"
        ],
        [
          "irregular",
          "irregular"
        ],
        [
          "star cluster",
          "star cluster"
        ],
        [
          "star",
          "star"
        ]
      ],
      "raw_glosses": [
        "(astronomy) a more or less irregular star cluster containing tens to thousands of stars"
      ],
      "related": [
        {
          "word": "globular cluster"
        }
      ],
      "topics": [
        "astronomy",
        "natural-sciences"
      ],
      "translations": [
        {
          "code": "eo",
          "lang": "Esperanto",
          "sense": "large spherical star cluster",
          "word": "malfermita stelamaso"
        },
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "large spherical star cluster",
          "word": "avoin tähtijoukko"
        },
        {
          "code": "fr",
          "lang": "French",
          "sense": "large spherical star cluster",
          "word": "amas ouvert"
        },
        {
          "alt": "さんかいせいだん",
          "code": "ja",
          "lang": "Japanese",
          "roman": "sankaiseidan",
          "sense": "large spherical star cluster",
          "word": "散開星団"
        }
      ],
      "wikipedia": [
        "open cluster"
      ]
    }
  ],
  "word": "open cluster"
}

{
  "forms": [
    {
      "form": "open clusters",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "open cluster (plural open clusters)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "globular cluster"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
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        "English multiword terms",
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        "Terms with Finnish translations",
        "Terms with French translations",
        "Terms with Japanese translations",
        "en:Astronomy"
      ],
      "glosses": [
        "a more or less irregular star cluster containing tens to thousands of stars"
      ],
      "links": [
        [
          "astronomy",
          "astronomy"
        ],
        [
          "irregular",
          "irregular"
        ],
        [
          "star cluster",
          "star cluster"
        ],
        [
          "star",
          "star"
        ]
      ],
      "raw_glosses": [
        "(astronomy) a more or less irregular star cluster containing tens to thousands of stars"
      ],
      "topics": [
        "astronomy",
        "natural-sciences"
      ],
      "wikipedia": [
        "open cluster"
      ]
    }
  ],
  "translations": [
    {
      "code": "eo",
      "lang": "Esperanto",
      "sense": "large spherical star cluster",
      "word": "malfermita stelamaso"
    },
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "large spherical star cluster",
      "word": "avoin tähtijoukko"
    },
    {
      "code": "fr",
      "lang": "French",
      "sense": "large spherical star cluster",
      "word": "amas ouvert"
    },
    {
      "alt": "さんかいせいだん",
      "code": "ja",
      "lang": "Japanese",
      "roman": "sankaiseidan",
      "sense": "large spherical star cluster",
      "word": "散開星団"
    }
  ],
  "word": "open cluster"
}