"Black Monday" meaning in English

{
  "head_templates": [
    {
      "args": {
        "head": "Black Monday"
      },
      "expansion": "Black Monday",
      "name": "en-proper noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "senses": [
    {
      "glosses": [
        "Any of certain Mondays when undesirable or turbulent events have occurred."
      ],
      "id": "en-Black_Monday-en-name-WQ9ponA0"
    },
    {
      "categories": [
        {
          "_dis": "15 49 37",
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
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          "source": "w+disamb"
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      ],
      "glosses": [
        "March 9, 2020, in the midst of the 2020 stock market crash, which resulted from market instability due to the COVID-19 pandemic. It was followed three days later by a similar event called Black Thursday."
      ],
      "id": "en-Black_Monday-en-name-Pyt85xU1",
      "links": [
        [
          "Black Thursday",
          "Black Thursday"
        ]
      ]
    },
    {
      "categories": [],
      "coordinate_terms": [
        {
          "_dis1": "22 17 61",
          "word": "Black Tuesday"
        },
        {
          "_dis1": "22 17 61",
          "word": "Black Thursday"
        },
        {
          "_dis1": "22 17 61",
          "word": "Black Friday"
        },
        {
          "_dis1": "22 17 61",
          "word": "blue Monday"
        }
      ],
      "glosses": [
        "The first Monday back at school after the holidays."
      ],
      "id": "en-Black_Monday-en-name-zlS-1QNK",
      "raw_glosses": [
        "(colloquial) The first Monday back at school after the holidays."
      ],
      "related": [
        {
          "_dis1": "22 17 60",
          "word": "Black Friday"
        },
        {
          "_dis1": "22 17 60",
          "english": "busy market day",
          "word": "Green Monday"
        }
      ],
      "tags": [
        "colloquial"
      ]
    }
  ],
  "word": "Black Monday"
}

{
  "categories": [
    "English entries with incorrect language header",
    "English lemmas",
    "English multiword terms",
    "English proper nouns",
    "English uncountable nouns"
  ],
  "coordinate_terms": [
    {
      "word": "Black Tuesday"
    },
    {
      "word": "Black Thursday"
    },
    {
      "word": "Black Friday"
    },
    {
      "word": "blue Monday"
    }
  ],
  "head_templates": [
    {
      "args": {
        "head": "Black Monday"
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      "expansion": "Black Monday",
      "name": "en-proper noun"
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  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "name",
  "related": [
    {
      "word": "Black Friday"
    },
    {
      "english": "busy market day",
      "word": "Green Monday"
    }
  ],
  "senses": [
    {
      "glosses": [
        "Any of certain Mondays when undesirable or turbulent events have occurred."
      ]
    },
    {
      "glosses": [
        "March 9, 2020, in the midst of the 2020 stock market crash, which resulted from market instability due to the COVID-19 pandemic. It was followed three days later by a similar event called Black Thursday."
      ],
      "links": [
        [
          "Black Thursday",
          "Black Thursday"
        ]
      ]
    },
    {
      "categories": [
        "English colloquialisms"
      ],
      "glosses": [
        "The first Monday back at school after the holidays."
      ],
      "raw_glosses": [
        "(colloquial) The first Monday back at school after the holidays."
      ],
      "tags": [
        "colloquial"
      ]
    }
  ],
  "word": "Black Monday"
}