"Five Boroughs" meaning in English

{
  "etymology_text": "From the organization of the City of New York into five boroughs, after the merger of (the now Manhattan) New York (City), New York (County), New York (State), with its surrounding cities.",
  "forms": [
    {
      "form": "The Five Boroughs",
      "tags": [
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    }
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      "expansion": "The Five Boroughs",
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  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
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          "parents": [
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      "glosses": [
        "Synonym of New York City"
      ],
      "id": "en-Five_Boroughs-en-name-GRdDxXm7",
      "links": [
        [
          "New York City",
          "New York City#English"
        ]
      ],
      "raw_glosses": [
        "(slang) Synonym of New York City"
      ],
      "synonyms": [
        {
          "tags": [
            "synonym",
            "synonym-of"
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          "word": "New York City"
        },
        {
          "word": "5 Boroughs"
        }
      ],
      "tags": [
        "slang"
      ]
    }
  ],
  "word": "Five Boroughs"
}

{
  "etymology_text": "From the organization of the City of New York into five boroughs, after the merger of (the now Manhattan) New York (City), New York (County), New York (State), with its surrounding cities.",
  "forms": [
    {
      "form": "The Five Boroughs",
      "tags": [
        "canonical"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "The Five Boroughs"
      },
      "expansion": "The Five Boroughs",
      "name": "en-proper-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English proper nouns",
        "English slang",
        "English uncountable nouns",
        "Pages with 1 entry",
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      ],
      "glosses": [
        "Synonym of New York City"
      ],
      "links": [
        [
          "New York City",
          "New York City#English"
        ]
      ],
      "raw_glosses": [
        "(slang) Synonym of New York City"
      ],
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          "word": "New York City"
        }
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  "synonyms": [
    {
      "word": "5 Boroughs"
    }
  ],
  "word": "Five Boroughs"
}