"screen door on a submarine" meaning in English

{
  "etymology_text": "A screen door on a submarine would be absurd as it would allow the vessel to fill with water.",
  "forms": [
    {
      "form": "screen doors on a submarine",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "screen doors on submarines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "screen doors on a submarine",
        "2": "screen doors on submarines"
      },
      "expansion": "screen door on a submarine (plural screen doors on a submarine or screen doors on submarines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              124,
              150
            ]
          ],
          "ref": "1995, The Economist, volume 336, numbers 7921-7925, Economist Newspaper Limited:",
          "text": "But realists put the final number of jobs saved through privatisation at no more than 800. \"It's about as useful to us as a screen door on a submarine,\" says an angry mayor's office in Sacramento .",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              178,
              204
            ]
          ],
          "ref": "2005 July, Rich Beattie, “Trigger Happy”, in Boating, volume 78, number 7, →ISSN, page 123:",
          "text": "I doubt anybody would give you static about unloaded and stored long guns anywhere in U.S. waters, and few places would about handguns (although unloaded guns are as useful as a screen door on a submarine).”",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              128,
              154
            ]
          ],
          "ref": "2016, Rocky Heckman, Designing Platform Independent Mobile Apps and Services, John Wiley & Sons, →ISBN:",
          "text": "If you don't know what security vulnerabilities look like at the code level, then having the source code is just as useful as a screen door on a submarine from a security perspective.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Something that is useless or absurd."
      ],
      "id": "en-screen_door_on_a_submarine-en-noun-8UtjLh7Z",
      "links": [
        [
          "useless",
          "useless"
        ],
        [
          "absurd",
          "absurd"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) Something that is useless or absurd."
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "word": "screen door on a submarine"
}

{
  "etymology_text": "A screen door on a submarine would be absurd as it would allow the vessel to fill with water.",
  "forms": [
    {
      "form": "screen doors on a submarine",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "screen doors on submarines",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "screen doors on a submarine",
        "2": "screen doors on submarines"
      },
      "expansion": "screen door on a submarine (plural screen doors on a submarine or screen doors on submarines)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English idioms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "bold_text_offsets": [
            [
              124,
              150
            ]
          ],
          "ref": "1995, The Economist, volume 336, numbers 7921-7925, Economist Newspaper Limited:",
          "text": "But realists put the final number of jobs saved through privatisation at no more than 800. \"It's about as useful to us as a screen door on a submarine,\" says an angry mayor's office in Sacramento .",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              178,
              204
            ]
          ],
          "ref": "2005 July, Rich Beattie, “Trigger Happy”, in Boating, volume 78, number 7, →ISSN, page 123:",
          "text": "I doubt anybody would give you static about unloaded and stored long guns anywhere in U.S. waters, and few places would about handguns (although unloaded guns are as useful as a screen door on a submarine).”",
          "type": "quotation"
        },
        {
          "bold_text_offsets": [
            [
              128,
              154
            ]
          ],
          "ref": "2016, Rocky Heckman, Designing Platform Independent Mobile Apps and Services, John Wiley & Sons, →ISBN:",
          "text": "If you don't know what security vulnerabilities look like at the code level, then having the source code is just as useful as a screen door on a submarine from a security perspective.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Something that is useless or absurd."
      ],
      "links": [
        [
          "useless",
          "useless"
        ],
        [
          "absurd",
          "absurd"
        ]
      ],
      "raw_glosses": [
        "(idiomatic) Something that is useless or absurd."
      ],
      "tags": [
        "idiomatic"
      ]
    }
  ],
  "word": "screen door on a submarine"
}