"mustn't" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "must",
        "3": "n't"
      },
      "expansion": "must + -n't",
      "name": "suffix"
    }
  ],
  "etymology_text": "must + -n't",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "verb form"
      },
      "expansion": "mustn't",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms suffixed with -n't",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Entries with translation boxes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Esperanto translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Maori translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Polish translations",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Terms with Scots translations",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              4,
              11
            ]
          ],
          "text": "You mustn't blame yourself for this tragedy.",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              12,
              19
            ]
          ],
          "text": "We must go, mustn't we?",
          "type": "example"
        },
        {
          "text": "1906, Edith Nesbit, The Railway Children, Chapter 4: The engine-burglar,\n\"Now, listen,\" said Mother; \"it's quite true that we're poor, but we have enough to live on. You mustn't go telling everyone about our affairs--it's not right. And you must never, never, never ask strangers to give you things. Now always remember that--won't you?\""
        },
        {
          "ref": "1989: Batman (movie)",
          "text": "Look, we mustn't mistake ourselves for regular people. We're artists."
        }
      ],
      "glosses": [
        "must not (negative auxiliary); used to indicate that something is forbidden or, in a tag question, that something is not necessary."
      ],
      "id": "en-mustn't-en-verb-WdAC8eUP",
      "links": [
        [
          "must",
          "must"
        ],
        [
          "not",
          "not"
        ],
        [
          "forbidden",
          "forbidden#English"
        ],
        [
          "tag question",
          "tag question#English"
        ]
      ],
      "raw_glosses": [
        "(uncommon) must not (negative auxiliary); used to indicate that something is forbidden or, in a tag question, that something is not necessary."
      ],
      "related": [
        {
          "word": "shouldn't"
        },
        {
          "word": "can't"
        },
        {
          "word": "oughtn't"
        }
      ],
      "tags": [
        "uncommon"
      ],
      "translations": [
        {
          "code": "eo",
          "lang": "Esperanto",
          "lang_code": "eo",
          "sense": "something is forbidden",
          "word": "ne devas"
        },
        {
          "code": "mi",
          "lang": "Maori",
          "lang_code": "mi",
          "note": "+ verb",
          "sense": "something is forbidden",
          "word": "me kaua"
        },
        {
          "code": "pl",
          "lang": "Polish",
          "lang_code": "pl",
          "sense": "something is forbidden",
          "tags": [
            "imperfective"
          ],
          "word": "nie wolno"
        },
        {
          "code": "sco",
          "lang": "Scots",
          "lang_code": "sco",
          "sense": "something is forbidden",
          "word": "maunna"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈmʌs.n̩t/"
    },
    {
      "audio": "en-US mustn't.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/d/d5/En-US_mustn%27t.ogg/En-US_mustn%27t.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/d/d5/En-US_mustn%27t.ogg"
    }
  ],
  "word": "mustn't"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "must",
        "3": "n't"
      },
      "expansion": "must + -n't",
      "name": "suffix"
    }
  ],
  "etymology_text": "must + -n't",
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "verb form"
      },
      "expansion": "mustn't",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "verb",
  "related": [
    {
      "word": "shouldn't"
    },
    {
      "word": "can't"
    },
    {
      "word": "oughtn't"
    }
  ],
  "senses": [
    {
      "categories": [
        "English auxiliary verb forms",
        "English contractions",
        "English defective verbs",
        "English entries with incorrect language header",
        "English non-lemma forms",
        "English terms suffixed with -n't",
        "English terms with uncommon senses",
        "English terms with usage examples",
        "English verb forms",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Esperanto translations",
        "Terms with Maori translations",
        "Terms with Polish translations",
        "Terms with Scots translations"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              4,
              11
            ]
          ],
          "text": "You mustn't blame yourself for this tragedy.",
          "type": "example"
        },
        {
          "bold_text_offsets": [
            [
              12,
              19
            ]
          ],
          "text": "We must go, mustn't we?",
          "type": "example"
        },
        {
          "text": "1906, Edith Nesbit, The Railway Children, Chapter 4: The engine-burglar,\n\"Now, listen,\" said Mother; \"it's quite true that we're poor, but we have enough to live on. You mustn't go telling everyone about our affairs--it's not right. And you must never, never, never ask strangers to give you things. Now always remember that--won't you?\""
        },
        {
          "ref": "1989: Batman (movie)",
          "text": "Look, we mustn't mistake ourselves for regular people. We're artists."
        }
      ],
      "glosses": [
        "must not (negative auxiliary); used to indicate that something is forbidden or, in a tag question, that something is not necessary."
      ],
      "links": [
        [
          "must",
          "must"
        ],
        [
          "not",
          "not"
        ],
        [
          "forbidden",
          "forbidden#English"
        ],
        [
          "tag question",
          "tag question#English"
        ]
      ],
      "raw_glosses": [
        "(uncommon) must not (negative auxiliary); used to indicate that something is forbidden or, in a tag question, that something is not necessary."
      ],
      "tags": [
        "uncommon"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈmʌs.n̩t/"
    },
    {
      "audio": "en-US mustn't.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/d/d5/En-US_mustn%27t.ogg/En-US_mustn%27t.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/d/d5/En-US_mustn%27t.ogg"
    }
  ],
  "translations": [
    {
      "code": "eo",
      "lang": "Esperanto",
      "lang_code": "eo",
      "sense": "something is forbidden",
      "word": "ne devas"
    },
    {
      "code": "mi",
      "lang": "Maori",
      "lang_code": "mi",
      "note": "+ verb",
      "sense": "something is forbidden",
      "word": "me kaua"
    },
    {
      "code": "pl",
      "lang": "Polish",
      "lang_code": "pl",
      "sense": "something is forbidden",
      "tags": [
        "imperfective"
      ],
      "word": "nie wolno"
    },
    {
      "code": "sco",
      "lang": "Scots",
      "lang_code": "sco",
      "sense": "something is forbidden",
      "word": "maunna"
    }
  ],
  "word": "mustn't"
}