"letdown" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": ":deverbal",
        "3": "let down",
        "text": "+",
        "tree": "1"
      },
      "expansion": "Etymology tree\nEnglish let downdeverb.\nEnglish letdown\n[Appendix:Glossary#deverbal|Deverbal]] from\", \"terms\" : [ { \"children\" : [ ], \"lang_name\" : \"English\", \"term\" : \"let down\", \"status\" : \"missing\", \"lang\" : \"en\" } ], \"keyword\" : \"deverbal\" } ], \"lang_name\" : \"English\", \"term\" : \"letdown\", \"status\" : \"ok\", \"lang\" : \"en\" }\" data-lang=\"en\" data-title=\"letdown\">\nDeverbal from let down.",
      "name": "ety"
    }
  ],
  "etymology_text": "Etymology tree\nEnglish let downdeverb.\nEnglish letdown\nDeverbal from let down.",
  "forms": [
    {
      "form": "letdowns",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "letdown (countable and uncountable, plural letdowns)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "let-down"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English deverbals",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries referencing missing etymons",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with etymology texts",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with etymology trees",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages using etymon with no ID",
          "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": "Pages with etymology trees",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Alternative form of let-down."
      ],
      "id": "en-letdown-en-noun--1B4~fCk",
      "links": [
        [
          "let-down",
          "let-down#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "letdown"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": ":deverbal",
        "3": "let down",
        "text": "+",
        "tree": "1"
      },
      "expansion": "Etymology tree\nEnglish let downdeverb.\nEnglish letdown\n[Appendix:Glossary#deverbal|Deverbal]] from\", \"terms\" : [ { \"children\" : [ ], \"lang_name\" : \"English\", \"term\" : \"let down\", \"status\" : \"missing\", \"lang\" : \"en\" } ], \"keyword\" : \"deverbal\" } ], \"lang_name\" : \"English\", \"term\" : \"letdown\", \"status\" : \"ok\", \"lang\" : \"en\" }\" data-lang=\"en\" data-title=\"letdown\">\nDeverbal from let down.",
      "name": "ety"
    }
  ],
  "etymology_text": "Etymology tree\nEnglish let downdeverb.\nEnglish letdown\nDeverbal from let down.",
  "forms": [
    {
      "form": "letdowns",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "~"
      },
      "expansion": "letdown (countable and uncountable, plural letdowns)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "let-down"
        }
      ],
      "categories": [
        "English countable nouns",
        "English deverbals",
        "English entries referencing missing etymons",
        "English entries with etymology texts",
        "English entries with etymology trees",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English uncountable nouns",
        "Pages using etymon with no ID",
        "Pages with 1 entry",
        "Pages with entries",
        "Pages with etymology trees"
      ],
      "glosses": [
        "Alternative form of let-down."
      ],
      "links": [
        [
          "let-down",
          "let-down#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative",
        "countable",
        "uncountable"
      ]
    }
  ],
  "word": "letdown"
}