"plan B" meaning in English

{
  "forms": [
    {
      "form": "plan Bs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "plan B (countable and uncountable, plural plan Bs)",
      "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 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "After failing to find a wife by 40, he had to rely on plan B, a mail-order bride.",
          "type": "example"
        },
        {
          "ref": "2016, A.K. Brown, Jumpstart (Champagne Universe Series: Book 1), page 3:",
          "text": "She needed something else...A backup plan, a plan \"B\".",
          "type": "quote"
        },
        {
          "ref": "2022 September 21, Chris Green tells Nick Brodrick, “It's absolutely my favourite train”, in RAIL, number 966, page 35:",
          "text": "\"There was no plan B, other than the Pendolino would have to run in non-tilt mode at 110mph.\" [...].",
          "type": "quote"
        }
      ],
      "glosses": [
        "An alternative approach adopted when one's original plan does not succeed."
      ],
      "id": "en-plan_B-en-noun-6Au~B~VI",
      "links": [
        [
          "alternative",
          "alternative"
        ],
        [
          "approach",
          "approach"
        ],
        [
          "adopt",
          "adopt"
        ],
        [
          "original",
          "original"
        ],
        [
          "plan",
          "plan"
        ],
        [
          "succeed",
          "succeed"
        ]
      ],
      "related": [
        {
          "word": "change one's battery"
        },
        {
          "word": "there is no Planet B"
        }
      ],
      "synonyms": [
        {
          "word": "contingency plan"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "plan B"
}

{
  "forms": [
    {
      "form": "plan Bs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "plan B (countable and uncountable, plural plan Bs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "change one's battery"
    },
    {
      "word": "there is no Planet B"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "English terms with usage examples",
        "English uncountable nouns",
        "Pages with 2 entries",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "After failing to find a wife by 40, he had to rely on plan B, a mail-order bride.",
          "type": "example"
        },
        {
          "ref": "2016, A.K. Brown, Jumpstart (Champagne Universe Series: Book 1), page 3:",
          "text": "She needed something else...A backup plan, a plan \"B\".",
          "type": "quote"
        },
        {
          "ref": "2022 September 21, Chris Green tells Nick Brodrick, “It's absolutely my favourite train”, in RAIL, number 966, page 35:",
          "text": "\"There was no plan B, other than the Pendolino would have to run in non-tilt mode at 110mph.\" [...].",
          "type": "quote"
        }
      ],
      "glosses": [
        "An alternative approach adopted when one's original plan does not succeed."
      ],
      "links": [
        [
          "alternative",
          "alternative"
        ],
        [
          "approach",
          "approach"
        ],
        [
          "adopt",
          "adopt"
        ],
        [
          "original",
          "original"
        ],
        [
          "plan",
          "plan"
        ],
        [
          "succeed",
          "succeed"
        ]
      ],
      "synonyms": [
        {
          "word": "contingency plan"
        }
      ],
      "tags": [
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "plan B"
}