"5.56" meaning in Translingual

{
  "etymology_text": "From 5.56 millimetres, the internal diameter, from the top of the lands in the barrel rifling. (the bullet calibre would be 5.664 mm (0.223\")).",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "noun"
      },
      "expansion": "5.56",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Translingual entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "mul",
          "name": "Firearms",
          "orig": "mul:Firearms",
          "parents": [
            "Weapons",
            "Hunting",
            "Military",
            "Tools",
            "Human activity",
            "Society",
            "Technology",
            "Human behaviour",
            "All topics",
            "Human",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "derived": [
        {
          "word": "5.56 NATO"
        },
        {
          "word": "5.56x45"
        },
        {
          "word": "5.56x45 NATO"
        }
      ],
      "glosses": [
        "A common calibre of firearm"
      ],
      "id": "en-5.56-mul-noun-fR2yWsX2",
      "links": [
        [
          "firearm",
          "firearm"
        ],
        [
          "calibre",
          "calibre#English"
        ]
      ],
      "raw_glosses": [
        "(firearms) A common calibre of firearm"
      ],
      "related": [
        {
          "word": "7.62"
        }
      ],
      "synonyms": [
        {
          "word": ".223"
        }
      ],
      "topics": [
        "engineering",
        "firearms",
        "government",
        "military",
        "natural-sciences",
        "physical-sciences",
        "politics",
        "tools",
        "war",
        "weaponry"
      ]
    }
  ],
  "word": "5.56"
}

{
  "derived": [
    {
      "word": "5.56 NATO"
    },
    {
      "word": "5.56x45"
    },
    {
      "word": "5.56x45 NATO"
    }
  ],
  "etymology_text": "From 5.56 millimetres, the internal diameter, from the top of the lands in the barrel rifling. (the bullet calibre would be 5.664 mm (0.223\")).",
  "head_templates": [
    {
      "args": {
        "1": "mul",
        "2": "noun"
      },
      "expansion": "5.56",
      "name": "head"
    }
  ],
  "lang": "Translingual",
  "lang_code": "mul",
  "pos": "noun",
  "related": [
    {
      "word": "7.62"
    }
  ],
  "senses": [
    {
      "categories": [
        "Pages with 1 entry",
        "Pages with entries",
        "Translingual entries with incorrect language header",
        "Translingual lemmas",
        "Translingual nouns",
        "Translingual terms spelled with .",
        "Translingual terms spelled with numbers",
        "mul:Firearms"
      ],
      "glosses": [
        "A common calibre of firearm"
      ],
      "links": [
        [
          "firearm",
          "firearm"
        ],
        [
          "calibre",
          "calibre#English"
        ]
      ],
      "raw_glosses": [
        "(firearms) A common calibre of firearm"
      ],
      "topics": [
        "engineering",
        "firearms",
        "government",
        "military",
        "natural-sciences",
        "physical-sciences",
        "politics",
        "tools",
        "war",
        "weaponry"
      ]
    }
  ],
  "synonyms": [
    {
      "word": ".223"
    }
  ],
  "word": "5.56"
}