"FNU" meaning in English

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  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
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          "extra": "used on birth certificates or airline reservations",
          "word": "first name unknown"
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      "categories": [
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Aviation",
          "orig": "en:Aviation",
          "parents": [
            "Aeronautics",
            "Transport",
            "Sciences",
            "All topics",
            "Fundamental"
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          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Travel",
          "orig": "en:Travel",
          "parents": [
            "Human activity",
            "Transport",
            "Human behaviour",
            "All topics",
            "Human",
            "Fundamental"
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          "_dis": "68 32",
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      "glosses": [
        "Initialism of first name unknown. (used on birth certificates or airline reservations)"
      ],
      "id": "en-FNU-en-phrase-1McSqBf-",
      "links": [
        [
          "travel",
          "travel"
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        [
          "aviation",
          "aviation"
        ],
        [
          "first name",
          "first name#English"
        ],
        [
          "unknown",
          "unknown#English"
        ]
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      "raw_glosses": [
        "(travel, aviation) Initialism of first name unknown. (used on birth certificates or airline reservations)"
      ],
      "tags": [
        "abbreviation",
        "alt-of",
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      ],
      "topics": [
        "aeronautics",
        "aerospace",
        "aviation",
        "business",
        "engineering",
        "lifestyle",
        "natural-sciences",
        "physical-sciences",
        "tourism",
        "transport",
        "travel"
      ]
    },
    {
      "alt_of": [
        {
          "extra": "a turbidity measurement also known as Formazin Turbidity Unit (FTU)",
          "word": "Formazin Nephelometric Unit"
        }
      ],
      "categories": [],
      "glosses": [
        "Initialism of Formazin Nephelometric Unit, a turbidity measurement also known as Formazin Turbidity Unit (FTU)"
      ],
      "id": "en-FNU-en-phrase-gb-84m3N",
      "links": [
        [
          "turbidity",
          "turbidity"
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "initialism"
      ]
    }
  ],
  "word": "FNU"
}

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  "lang": "English",
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  "pos": "phrase",
  "senses": [
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        {
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        "en:Travel"
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      "glosses": [
        "Initialism of first name unknown. (used on birth certificates or airline reservations)"
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        [
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          "travel"
        ],
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          "aviation",
          "aviation"
        ],
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          "first name",
          "first name#English"
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          "unknown",
          "unknown#English"
        ]
      ],
      "raw_glosses": [
        "(travel, aviation) Initialism of first name unknown. (used on birth certificates or airline reservations)"
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "initialism"
      ],
      "topics": [
        "aeronautics",
        "aerospace",
        "aviation",
        "business",
        "engineering",
        "lifestyle",
        "natural-sciences",
        "physical-sciences",
        "tourism",
        "transport",
        "travel"
      ]
    },
    {
      "alt_of": [
        {
          "extra": "a turbidity measurement also known as Formazin Turbidity Unit (FTU)",
          "word": "Formazin Nephelometric Unit"
        }
      ],
      "categories": [
        "English initialisms"
      ],
      "glosses": [
        "Initialism of Formazin Nephelometric Unit, a turbidity measurement also known as Formazin Turbidity Unit (FTU)"
      ],
      "links": [
        [
          "turbidity",
          "turbidity"
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        "alt-of",
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  ],
  "word": "FNU"
}