"strong-box" meaning in English

{
  "forms": [
    {
      "form": "strong-boxes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "strong-box (plural strong-boxes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "strongbox"
        }
      ],
      "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"
        }
      ],
      "examples": [
        {
          "ref": "c. 1921 (date written), Karel Čapek, translated by Paul Selver, R.U.R. (Rossum’s Universal Robots): A Fantastic Melodrama […], Garden City, N.Y.: Doubleday, Page & Company, published 1923, →OCLC, Act 3:",
          "text": "Domin\n[Hoarsely]: Where's old Rossum's manuscript?\nBusman\nIn your strong-box, of course.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative form of strongbox"
      ],
      "id": "en-strong-box-en-noun--iSphaJO",
      "links": [
        [
          "strongbox",
          "strongbox#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "strong-box"
}

{
  "forms": [
    {
      "form": "strong-boxes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "strong-box (plural strong-boxes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "strongbox"
        }
      ],
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "c. 1921 (date written), Karel Čapek, translated by Paul Selver, R.U.R. (Rossum’s Universal Robots): A Fantastic Melodrama […], Garden City, N.Y.: Doubleday, Page & Company, published 1923, →OCLC, Act 3:",
          "text": "Domin\n[Hoarsely]: Where's old Rossum's manuscript?\nBusman\nIn your strong-box, of course.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative form of strongbox"
      ],
      "links": [
        [
          "strongbox",
          "strongbox#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "strong-box"
}