"sis" meaning in Ido

{
  "etymology_templates": [
    {
      "args": {
        "1": "io",
        "2": "en",
        "3": "six"
      },
      "expansion": "English six",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "fr",
        "3": "six"
      },
      "expansion": "French six",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "de",
        "3": "sechs"
      },
      "expansion": "German sechs",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "es",
        "3": "seis"
      },
      "expansion": "Spanish seis",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "it",
        "3": "sei"
      },
      "expansion": "Italian sei",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "ru",
        "3": "шесть"
      },
      "expansion": "Russian шесть (šestʹ)",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "ine-pro",
        "3": "*swéḱs"
      },
      "expansion": "Proto-Indo-European *swéḱs",
      "name": "der"
    }
  ],
  "etymology_text": "From English six, French six, German sechs, Spanish seis, Italian sei, Russian шесть (šestʹ), all ultimately from Proto-Indo-European *swéḱs.",
  "head_templates": [
    {
      "args": {
        "1": "io",
        "2": "numeral"
      },
      "expansion": "sis",
      "name": "head"
    }
  ],
  "lang": "Ido",
  "lang_code": "io",
  "pos": "num",
  "senses": [
    {
      "categories": [
        {
          "kind": "topical",
          "name": "Ido cardinal numbers",
          "parents": [
            "Cardinal numbers",
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Ido entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 23 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "six (6)"
      ],
      "id": "en-sis-io-num-pNZtnEPK",
      "links": [
        [
          "six",
          "six"
        ]
      ]
    }
  ],
  "word": "sis"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "io",
        "2": "en",
        "3": "six"
      },
      "expansion": "English six",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "fr",
        "3": "six"
      },
      "expansion": "French six",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "de",
        "3": "sechs"
      },
      "expansion": "German sechs",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "es",
        "3": "seis"
      },
      "expansion": "Spanish seis",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "it",
        "3": "sei"
      },
      "expansion": "Italian sei",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "ru",
        "3": "шесть"
      },
      "expansion": "Russian шесть (šestʹ)",
      "name": "der"
    },
    {
      "args": {
        "1": "io",
        "2": "ine-pro",
        "3": "*swéḱs"
      },
      "expansion": "Proto-Indo-European *swéḱs",
      "name": "der"
    }
  ],
  "etymology_text": "From English six, French six, German sechs, Spanish seis, Italian sei, Russian шесть (šestʹ), all ultimately from Proto-Indo-European *swéḱs.",
  "head_templates": [
    {
      "args": {
        "1": "io",
        "2": "numeral"
      },
      "expansion": "sis",
      "name": "head"
    }
  ],
  "lang": "Ido",
  "lang_code": "io",
  "pos": "num",
  "senses": [
    {
      "categories": [
        "Ido cardinal numbers",
        "Ido entries with incorrect language header",
        "Ido lemmas",
        "Ido numerals",
        "Ido palindromes",
        "Ido terms derived from English",
        "Ido terms derived from French",
        "Ido terms derived from German",
        "Ido terms derived from Italian",
        "Ido terms derived from Proto-Indo-European",
        "Ido terms derived from Russian",
        "Ido terms derived from Spanish",
        "Pages with 23 entries",
        "Pages with entries"
      ],
      "glosses": [
        "six (6)"
      ],
      "links": [
        [
          "six",
          "six"
        ]
      ]
    }
  ],
  "word": "sis"
}