"flood plain" meaning in English

{
  "forms": [
    {
      "form": "flood plains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flood plain (plural flood plains)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "floodplain"
        }
      ],
      "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 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2021 October 6, John Hillier, “Harringworth's magical viaduct”, in RAIL, number 941, pages 36–37:",
          "text": "It must have been the magnetism of the viaduct that towers over the village of Harringworth, and which crosses the flood plain of the River Welland on the border of Rutland and Northamptonshire, which drew my family to living close by when we moved to Britain's smallest county in the early 1990s.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative form of floodplain"
      ],
      "id": "en-flood_plain-en-noun-GM4WV38C",
      "links": [
        [
          "floodplain",
          "floodplain#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "flood plain"
}

{
  "forms": [
    {
      "form": "flood plains",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flood plain (plural flood plains)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "floodplain"
        }
      ],
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "2021 October 6, John Hillier, “Harringworth's magical viaduct”, in RAIL, number 941, pages 36–37:",
          "text": "It must have been the magnetism of the viaduct that towers over the village of Harringworth, and which crosses the flood plain of the River Welland on the border of Rutland and Northamptonshire, which drew my family to living close by when we moved to Britain's smallest county in the early 1990s.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative form of floodplain"
      ],
      "links": [
        [
          "floodplain",
          "floodplain#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "flood plain"
}