"Hanoverian rat" meaning in English

{
  "etymology_text": "The name was introduced by English naturalist Charles Waterton, a devout Catholic, as a slur on Protestant Hanoverians whose British rule began in 1714, shortly before the species first appeared in Britain.",
  "forms": [
    {
      "form": "Hanoverian rats",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Hanoverian rat (plural Hanoverian rats)",
      "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"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "lifeform",
          "langcode": "en",
          "name": "Murids",
          "orig": "en:Murids",
          "parents": [
            "Rodents",
            "Mammals",
            "Vertebrates",
            "Chordates",
            "Animals",
            "Lifeforms",
            "All topics",
            "Life",
            "Fundamental",
            "Nature"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "The brown rat, Rattus norvegicus."
      ],
      "id": "en-Hanoverian_rat-en-noun-RLZWNKl8",
      "links": [
        [
          "brown rat",
          "brown rat"
        ],
        [
          "Rattus norvegicus",
          "Rattus norvegicus#Translingual"
        ]
      ],
      "wikipedia": [
        "Charles Waterton",
        "House of Hanover"
      ]
    }
  ],
  "word": "Hanoverian rat"
}

{
  "etymology_text": "The name was introduced by English naturalist Charles Waterton, a devout Catholic, as a slur on Protestant Hanoverians whose British rule began in 1714, shortly before the species first appeared in Britain.",
  "forms": [
    {
      "form": "Hanoverian rats",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Hanoverian rat (plural Hanoverian rats)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Murids"
      ],
      "glosses": [
        "The brown rat, Rattus norvegicus."
      ],
      "links": [
        [
          "brown rat",
          "brown rat"
        ],
        [
          "Rattus norvegicus",
          "Rattus norvegicus#Translingual"
        ]
      ],
      "wikipedia": [
        "Charles Waterton",
        "House of Hanover"
      ]
    }
  ],
  "word": "Hanoverian rat"
}