"top sheet" meaning in English

{
  "forms": [
    {
      "form": "top sheets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "top sheet (plural top sheets)",
      "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": "Entries with translation boxes",
          "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": "Terms with Finnish translations",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "A bed sheet used between a bottom sheet and a blanket."
      ],
      "id": "en-top_sheet-en-noun-FozgwBFz",
      "links": [
        [
          "bed sheet",
          "bed sheet"
        ],
        [
          "bottom sheet",
          "bottom sheet"
        ],
        [
          "blanket",
          "blanket"
        ]
      ],
      "related": [
        {
          "word": "bottom sheet"
        },
        {
          "word": "flat sheet"
        }
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "top bed sheet",
          "word": "päällyslakana"
        }
      ]
    }
  ],
  "word": "top sheet"
}

{
  "forms": [
    {
      "form": "top sheets",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "top sheet (plural top sheets)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "bottom sheet"
    },
    {
      "word": "flat sheet"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Entries with translation boxes",
        "Pages with 1 entry",
        "Pages with entries",
        "Terms with Finnish translations"
      ],
      "glosses": [
        "A bed sheet used between a bottom sheet and a blanket."
      ],
      "links": [
        [
          "bed sheet",
          "bed sheet"
        ],
        [
          "bottom sheet",
          "bottom sheet"
        ],
        [
          "blanket",
          "blanket"
        ]
      ]
    }
  ],
  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "top bed sheet",
      "word": "päällyslakana"
    }
  ],
  "word": "top sheet"
}