"bettern't" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "better",
        "3": "n't"
      },
      "expansion": "better + -n't",
      "name": "suffix"
    }
  ],
  "etymology_text": "better + -n't",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "verb form"
      },
      "expansion": "bettern't",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -n't",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2004, Kate Burridge, Weeds in the garden of words, page 119:",
          "text": "I better pull over, bettern't I?",
          "type": "quote"
        }
      ],
      "glosses": [
        "[[[had]]] better not (used in a tag question)."
      ],
      "id": "en-bettern't-en-verb-tf-kzPiq",
      "links": [
        [
          "better",
          "better"
        ],
        [
          "not",
          "not"
        ],
        [
          "tag question",
          "tag question"
        ]
      ],
      "raw_glosses": [
        "(nonstandard) [[[had]]] better not (used in a tag question)."
      ],
      "tags": [
        "nonstandard"
      ]
    }
  ],
  "word": "bettern't"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "better",
        "3": "n't"
      },
      "expansion": "better + -n't",
      "name": "suffix"
    }
  ],
  "etymology_text": "better + -n't",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "verb form"
      },
      "expansion": "bettern't",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        "English contractions",
        "English entries with incorrect language header",
        "English non-lemma forms",
        "English nonstandard terms",
        "English terms suffixed with -n't",
        "English terms with quotations",
        "English verb forms",
        "Pages with 1 entry",
        "Pages with entries",
        "Quotation templates to be cleaned"
      ],
      "examples": [
        {
          "ref": "2004, Kate Burridge, Weeds in the garden of words, page 119:",
          "text": "I better pull over, bettern't I?",
          "type": "quote"
        }
      ],
      "glosses": [
        "[[[had]]] better not (used in a tag question)."
      ],
      "links": [
        [
          "better",
          "better"
        ],
        [
          "not",
          "not"
        ],
        [
          "tag question",
          "tag question"
        ]
      ],
      "raw_glosses": [
        "(nonstandard) [[[had]]] better not (used in a tag question)."
      ],
      "tags": [
        "nonstandard"
      ]
    }
  ],
  "word": "bettern't"
}