"hospital corner" meaning in English

{
  "etymology_text": "Beds in a hospital might be made up in this way.",
  "forms": [
    {
      "form": "hospital corners",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hospital corner (plural hospital corners)",
      "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 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Bedding",
          "orig": "en:Bedding",
          "parents": [
            "Home",
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A crisp fold formed at the corner of a bed by tucking the sheet or blanket tightly under the edges of the mattress."
      ],
      "id": "en-hospital_corner-en-noun-BJLfqd0X",
      "links": [
        [
          "sheet",
          "sheet"
        ],
        [
          "blanket",
          "blanket"
        ],
        [
          "mattress",
          "mattress"
        ]
      ],
      "raw_glosses": [
        "(usually in the plural) A crisp fold formed at the corner of a bed by tucking the sheet or blanket tightly under the edges of the mattress."
      ],
      "tags": [
        "plural-normally"
      ]
    }
  ],
  "word": "hospital corner"
}

{
  "etymology_text": "Beds in a hospital might be made up in this way.",
  "forms": [
    {
      "form": "hospital corners",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "hospital corner (plural hospital corners)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Bedding"
      ],
      "glosses": [
        "A crisp fold formed at the corner of a bed by tucking the sheet or blanket tightly under the edges of the mattress."
      ],
      "links": [
        [
          "sheet",
          "sheet"
        ],
        [
          "blanket",
          "blanket"
        ],
        [
          "mattress",
          "mattress"
        ]
      ],
      "raw_glosses": [
        "(usually in the plural) A crisp fold formed at the corner of a bed by tucking the sheet or blanket tightly under the edges of the mattress."
      ],
      "tags": [
        "plural-normally"
      ]
    }
  ],
  "word": "hospital corner"
}