"guard rail" meaning in English

{
  "forms": [
    {
      "form": "guard rails",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "guard rail (plural guard rails)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "guardrail"
        }
      ],
      "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 2 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2022 March 23, Philip Haigh, “Network News: Driver of ScotRail HST had only seconds to react, says RAIB”, in RAIL, number 953, page 11:",
          "text": "Likewise, guard rails would have made little difference. They are fitted to the track to contain derailed wheels on the approach to tunnel portals or bridge parapets.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative spelling of guardrail"
      ],
      "id": "en-guard_rail-en-noun-ykXaUVcn",
      "links": [
        [
          "guardrail",
          "guardrail#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "guard rail"
}

{
  "forms": [
    {
      "form": "guard rails",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "guard rail (plural guard rails)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "word": "guardrail"
        }
      ],
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Pages with 2 entries",
        "Pages with entries"
      ],
      "examples": [
        {
          "ref": "2022 March 23, Philip Haigh, “Network News: Driver of ScotRail HST had only seconds to react, says RAIB”, in RAIL, number 953, page 11:",
          "text": "Likewise, guard rails would have made little difference. They are fitted to the track to contain derailed wheels on the approach to tunnel portals or bridge parapets.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Alternative spelling of guardrail"
      ],
      "links": [
        [
          "guardrail",
          "guardrail#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "guard rail"
}