"jäin" meaning in Finnish

{
  "etymology_number": 1,
  "head_templates": [
    {
      "args": {
        "1": "fi",
        "2": "noun form"
      },
      "expansion": "jäin",
      "name": "head"
    }
  ],
  "lang": "Finnish",
  "lang_code": "fi",
  "pos": "noun",
  "senses": [
    {
      "form_of": [
        {
          "word": "jää"
        }
      ],
      "glosses": [
        "instructive plural of jää"
      ],
      "id": "en-jäin-fi-noun-1pLKG0uW",
      "links": [
        [
          "jää",
          "jää#Finnish"
        ]
      ],
      "tags": [
        "form-of",
        "instructive",
        "plural"
      ]
    }
  ],
  "word": "jäin"
}

{
  "etymology_number": 2,
  "head_templates": [
    {
      "args": {
        "1": "fi",
        "2": "verb form"
      },
      "expansion": "jäin",
      "name": "head"
    }
  ],
  "lang": "Finnish",
  "lang_code": "fi",
  "pos": "verb",
  "senses": [
    {
      "categories": [
        {
          "_dis": "9 91",
          "kind": "other",
          "name": "Finnish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w+disamb"
        }
      ],
      "form_of": [
        {
          "word": "jäädä"
        }
      ],
      "glosses": [
        "first-person singular past indicative of jäädä"
      ],
      "id": "en-jäin-fi-verb-P6ovVZBo",
      "links": [
        [
          "jäädä",
          "jäädä#Finnish"
        ]
      ],
      "tags": [
        "first-person",
        "form-of",
        "indicative",
        "past",
        "singular"
      ]
    }
  ],
  "word": "jäin"
}

{
  "categories": [
    "Finnish entries with incorrect language header",
    "Finnish non-lemma forms",
    "Finnish noun forms",
    "Finnish verb forms"
  ],
  "etymology_number": 1,
  "head_templates": [
    {
      "args": {
        "1": "fi",
        "2": "noun form"
      },
      "expansion": "jäin",
      "name": "head"
    }
  ],
  "lang": "Finnish",
  "lang_code": "fi",
  "pos": "noun",
  "senses": [
    {
      "form_of": [
        {
          "word": "jää"
        }
      ],
      "glosses": [
        "instructive plural of jää"
      ],
      "links": [
        [
          "jää",
          "jää#Finnish"
        ]
      ],
      "tags": [
        "form-of",
        "instructive",
        "plural"
      ]
    }
  ],
  "word": "jäin"
}

{
  "categories": [
    "Finnish entries with incorrect language header",
    "Finnish non-lemma forms",
    "Finnish verb forms"
  ],
  "etymology_number": 2,
  "head_templates": [
    {
      "args": {
        "1": "fi",
        "2": "verb form"
      },
      "expansion": "jäin",
      "name": "head"
    }
  ],
  "lang": "Finnish",
  "lang_code": "fi",
  "pos": "verb",
  "senses": [
    {
      "form_of": [
        {
          "word": "jäädä"
        }
      ],
      "glosses": [
        "first-person singular past indicative of jäädä"
      ],
      "links": [
        [
          "jäädä",
          "jäädä#Finnish"
        ]
      ],
      "tags": [
        "first-person",
        "form-of",
        "indicative",
        "past",
        "singular"
      ]
    }
  ],
  "word": "jäin"
}