"lockdown browser" meaning in English

{
  "forms": [
    {
      "form": "lockdown browsers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "lockdown browser (plural lockdown browsers)",
      "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": "topical",
          "langcode": "en",
          "name": "Education",
          "orig": "en:Education",
          "parents": [
            "Society",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Software",
          "orig": "en:Software",
          "parents": [
            "Computing",
            "Media",
            "Technology",
            "Communication",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A software package, essentially a restricted web browser, that prevents users from navigating away from a particular online task, commonly used when holding tests, quizzes, etc."
      ],
      "id": "en-lockdown_browser-en-noun-pm66OArX",
      "links": [
        [
          "education",
          "education"
        ],
        [
          "web browser",
          "web browser"
        ]
      ],
      "raw_glosses": [
        "(education) A software package, essentially a restricted web browser, that prevents users from navigating away from a particular online task, commonly used when holding tests, quizzes, etc."
      ],
      "topics": [
        "education"
      ]
    }
  ],
  "word": "lockdown browser"
}

{
  "forms": [
    {
      "form": "lockdown browsers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "lockdown browser (plural lockdown browsers)",
      "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",
        "en:Education",
        "en:Software"
      ],
      "glosses": [
        "A software package, essentially a restricted web browser, that prevents users from navigating away from a particular online task, commonly used when holding tests, quizzes, etc."
      ],
      "links": [
        [
          "education",
          "education"
        ],
        [
          "web browser",
          "web browser"
        ]
      ],
      "raw_glosses": [
        "(education) A software package, essentially a restricted web browser, that prevents users from navigating away from a particular online task, commonly used when holding tests, quizzes, etc."
      ],
      "topics": [
        "education"
      ]
    }
  ],
  "word": "lockdown browser"
}