"RBG" meaning in English

{
  "head_templates": [
    {
      "args": {},
      "expansion": "RBG",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "alt_of": [
        {
          "word": "Ruth Bader Ginsburg"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Individuals",
          "orig": "en:Individuals",
          "parents": [
            "People",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "place",
          "langcode": "en",
          "name": "United States",
          "orig": "en:United States",
          "parents": [
            "North America",
            "America",
            "Earth",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Initialism of Ruth Bader Ginsburg."
      ],
      "id": "en-RBG-en-name-WI101YAp",
      "links": [
        [
          "Ruth Bader Ginsburg",
          "w:Ruth Bader Ginsburg"
        ]
      ],
      "raw_glosses": [
        "(informal) Initialism of Ruth Bader Ginsburg."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "informal",
        "initialism"
      ]
    }
  ],
  "word": "RBG"
}

{
  "head_templates": [
    {
      "args": {},
      "expansion": "RBG",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "alt_of": [
        {
          "word": "Ruth Bader Ginsburg"
        }
      ],
      "categories": [
        "English entries with incorrect language header",
        "English informal terms",
        "English initialisms",
        "English lemmas",
        "English proper nouns",
        "English uncountable nouns",
        "English words without vowels",
        "en:Individuals",
        "en:United States"
      ],
      "glosses": [
        "Initialism of Ruth Bader Ginsburg."
      ],
      "links": [
        [
          "Ruth Bader Ginsburg",
          "w:Ruth Bader Ginsburg"
        ]
      ],
      "raw_glosses": [
        "(informal) Initialism of Ruth Bader Ginsburg."
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "informal",
        "initialism"
      ]
    }
  ],
  "word": "RBG"
}