"nil" meaning in Interlingua

{
  "head_templates": [
    {
      "args": {
        "1": "ia",
        "2": "pronoun",
        "3": "indefinite"
      },
      "expansion": "nil (indefinite)",
      "name": "head"
    }
  ],
  "lang": "Interlingua",
  "lang_code": "ia",
  "pos": "pron",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Interlingua entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Interlingua pronouns",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 7 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "nothing"
      ],
      "id": "en-nil-ia-pron-F4XPw7xq",
      "links": [
        [
          "nothing",
          "nothing"
        ]
      ],
      "tags": [
        "indefinite"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/nil/"
    }
  ],
  "word": "nil"
}

{
  "categories": [
    "Pages using etymon with no ID",
    "Pages with 7 entries",
    "Pages with entries",
    "Pages with etymon",
    "Tok Pisin entries with etymon",
    "Tok Pisin entries with incorrect language header",
    "Tok Pisin lemmas",
    "Tok Pisin nouns",
    "Tok Pisin terms derived from English",
    "Tok Pisin terms derived from Middle English",
    "Tok Pisin terms derived from Old English",
    "Tok Pisin terms derived from Proto-Germanic",
    "Tok Pisin terms derived from Proto-Indo-European",
    "Tok Pisin terms derived from Proto-West Germanic",
    "Tok Pisin terms derived from the Proto-Indo-European root *(s)neh₁-"
  ],
  "head_templates": [
    {
      "args": {
        "1": "ia",
        "2": "pronoun",
        "3": "indefinite"
      },
      "expansion": "nil (indefinite)",
      "name": "head"
    }
  ],
  "lang": "Interlingua",
  "lang_code": "ia",
  "pos": "pron",
  "senses": [
    {
      "categories": [
        "Interlingua entries with incorrect language header",
        "Interlingua lemmas",
        "Interlingua pronouns",
        "Pages with 7 entries",
        "Pages with entries"
      ],
      "glosses": [
        "nothing"
      ],
      "links": [
        [
          "nothing",
          "nothing"
        ]
      ],
      "tags": [
        "indefinite"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/nil/"
    }
  ],
  "word": "nil"
}