"-ísima" meaning in Spanish

{
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "suffix form"
      },
      "expansion": "-ísima",
      "name": "head"
    }
  ],
  "hyphenation": [
    "-í‧si‧ma"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Spanish entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "word": "-ísimo"
        }
      ],
      "glosses": [
        "feminine singular of -ísimo"
      ],
      "id": "en--ísima-es-suffix-ig~QWt~M",
      "links": [
        [
          "-ísimo",
          "-ísimo#Spanish"
        ]
      ],
      "tags": [
        "feminine",
        "form-of",
        "morpheme",
        "singular"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈisima/"
    },
    {
      "ipa": "[ˈi.si.ma]"
    },
    {
      "rhymes": "-isima"
    }
  ],
  "word": "-ísima"
}

{
  "head_templates": [
    {
      "args": {
        "1": "es",
        "2": "suffix form"
      },
      "expansion": "-ísima",
      "name": "head"
    }
  ],
  "hyphenation": [
    "-í‧si‧ma"
  ],
  "lang": "Spanish",
  "lang_code": "es",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Pages with 1 entry",
        "Pages with entries",
        "Rhymes:Spanish/isima",
        "Rhymes:Spanish/isima/3 syllables",
        "Spanish 3-syllable words",
        "Spanish entries with incorrect language header",
        "Spanish non-lemma forms",
        "Spanish suffix forms",
        "Spanish terms with IPA pronunciation"
      ],
      "form_of": [
        {
          "word": "-ísimo"
        }
      ],
      "glosses": [
        "feminine singular of -ísimo"
      ],
      "links": [
        [
          "-ísimo",
          "-ísimo#Spanish"
        ]
      ],
      "tags": [
        "feminine",
        "form-of",
        "morpheme",
        "singular"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/ˈisima/"
    },
    {
      "ipa": "[ˈi.si.ma]"
    },
    {
      "rhymes": "-isima"
    }
  ],
  "word": "-ísima"
}