"flight bubble" meaning in English

{
  "forms": [
    {
      "form": "flight bubbles",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flight bubble (plural flight bubbles)",
      "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": "Coronavirus",
          "orig": "en:Coronavirus",
          "parents": [
            "Disease",
            "Health",
            "Body",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "An arrangement between two countries, states, or other administrative regions, that allows free air travel of residents between them while otherwise keeping their borders closed to travellers from outside the bubble."
      ],
      "id": "en-flight_bubble-en-noun-GWLOjU-n",
      "links": [
        [
          "arrangement",
          "arrangement"
        ],
        [
          "countries",
          "country"
        ],
        [
          "state",
          "state"
        ],
        [
          "administrative region",
          "administrative region"
        ],
        [
          "resident",
          "resident"
        ],
        [
          "border",
          "border"
        ]
      ]
    }
  ],
  "word": "flight bubble"
}

{
  "forms": [
    {
      "form": "flight bubbles",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "flight bubble (plural flight bubbles)",
      "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:Coronavirus"
      ],
      "glosses": [
        "An arrangement between two countries, states, or other administrative regions, that allows free air travel of residents between them while otherwise keeping their borders closed to travellers from outside the bubble."
      ],
      "links": [
        [
          "arrangement",
          "arrangement"
        ],
        [
          "countries",
          "country"
        ],
        [
          "state",
          "state"
        ],
        [
          "administrative region",
          "administrative region"
        ],
        [
          "resident",
          "resident"
        ],
        [
          "border",
          "border"
        ]
      ]
    }
  ],
  "word": "flight bubble"
}