"Newgate knocker" meaning in English

{
  "etymology_text": "Supposed to resemble the knocker on the prisoners' door at Newgate.",
  "forms": [
    {
      "form": "Newgate knockers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Newgate knocker (plural Newgate knockers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "British English",
          "parents": [],
          "source": "w"
        },
        {
          "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"
        }
      ],
      "glosses": [
        "A lock of hair worn twisted back toward the ear."
      ],
      "id": "en-Newgate_knocker-en-noun-6YHz-xd3",
      "links": [
        [
          "lock",
          "lock"
        ],
        [
          "hair",
          "hair"
        ],
        [
          "ear",
          "ear"
        ]
      ],
      "raw_glosses": [
        "(UK, slang, obsolete) A lock of hair worn twisted back toward the ear."
      ],
      "synonyms": [
        {
          "word": "aggravator"
        },
        {
          "word": "number six"
        }
      ],
      "tags": [
        "UK",
        "obsolete",
        "slang"
      ]
    }
  ],
  "word": "Newgate knocker"
}

{
  "etymology_text": "Supposed to resemble the knocker on the prisoners' door at Newgate.",
  "forms": [
    {
      "form": "Newgate knockers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Newgate knocker (plural Newgate knockers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "British English",
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English slang",
        "English terms with obsolete senses",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "A lock of hair worn twisted back toward the ear."
      ],
      "links": [
        [
          "lock",
          "lock"
        ],
        [
          "hair",
          "hair"
        ],
        [
          "ear",
          "ear"
        ]
      ],
      "raw_glosses": [
        "(UK, slang, obsolete) A lock of hair worn twisted back toward the ear."
      ],
      "synonyms": [
        {
          "word": "aggravator"
        },
        {
          "word": "number six"
        }
      ],
      "tags": [
        "UK",
        "obsolete",
        "slang"
      ]
    }
  ],
  "word": "Newgate knocker"
}