"include guard" meaning in English

{
  "forms": [
    {
      "form": "include guards",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "include guard (plural include guards)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "en",
          "name": "Programming",
          "orig": "en:Programming",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "In C and C++, a preprocessor directive used in header files to prevent them from being included multiple times."
      ],
      "id": "en-include_guard-en-noun-LnXzYrBB",
      "links": [
        [
          "programming",
          "programming#Noun"
        ],
        [
          "preprocessor",
          "preprocessor"
        ],
        [
          "directive",
          "directive"
        ],
        [
          "header file",
          "header file"
        ],
        [
          "include",
          "include"
        ]
      ],
      "raw_glosses": [
        "(programming) In C and C++, a preprocessor directive used in header files to prevent them from being included multiple times."
      ],
      "synonyms": [
        {
          "word": "header guard"
        },
        {
          "word": "macro guard"
        }
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "programming",
        "sciences"
      ]
    }
  ],
  "word": "include guard"
}

{
  "forms": [
    {
      "form": "include guards",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "include guard (plural include guards)",
      "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:Programming"
      ],
      "glosses": [
        "In C and C++, a preprocessor directive used in header files to prevent them from being included multiple times."
      ],
      "links": [
        [
          "programming",
          "programming#Noun"
        ],
        [
          "preprocessor",
          "preprocessor"
        ],
        [
          "directive",
          "directive"
        ],
        [
          "header file",
          "header file"
        ],
        [
          "include",
          "include"
        ]
      ],
      "raw_glosses": [
        "(programming) In C and C++, a preprocessor directive used in header files to prevent them from being included multiple times."
      ],
      "topics": [
        "computing",
        "engineering",
        "mathematics",
        "natural-sciences",
        "physical-sciences",
        "programming",
        "sciences"
      ]
    }
  ],
  "synonyms": [
    {
      "word": "header guard"
    },
    {
      "word": "macro guard"
    }
  ],
  "word": "include guard"
}