"sineistä" meaning in Finnois

{
  "categories": [
    {
      "kind": "other",
      "name": "Formes de noms communs en finnois",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Finnois",
      "orig": "finnois",
      "parents": [],
      "source": "w"
    }
  ],
  "lang": "Finnois",
  "lang_code": "fi",
  "pos": "noun",
  "pos_title": "Forme de nom commun",
  "senses": [
    {
      "form_of": [
        {
          "word": "sini"
        }
      ],
      "glosses": [
        "Élatif pluriel de sini."
      ],
      "id": "fr-sineistä-fi-noun-iiDHIsV3"
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈsineistæ\\"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "sineistä"
}

{
  "categories": [
    "Formes de noms communs en finnois",
    "finnois"
  ],
  "lang": "Finnois",
  "lang_code": "fi",
  "pos": "noun",
  "pos_title": "Forme de nom commun",
  "senses": [
    {
      "form_of": [
        {
          "word": "sini"
        }
      ],
      "glosses": [
        "Élatif pluriel de sini."
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈsineistæ\\"
    }
  ],
  "tags": [
    "form-of"
  ],
  "word": "sineistä"
}