"pienissimo" meaning in Italian

{
  "etymology_templates": [
    {
      "args": {
        "1": "it",
        "2": "pieno",
        "3": "-issimo"
      },
      "expansion": "pieno + -issimo",
      "name": "af"
    }
  ],
  "etymology_text": "From pieno + -issimo.",
  "forms": [
    {
      "form": "pienissima",
      "tags": [
        "feminine"
      ]
    },
    {
      "form": "pienissimi",
      "tags": [
        "masculine",
        "plural"
      ]
    },
    {
      "form": "pienissime",
      "tags": [
        "feminine",
        "plural"
      ]
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Italian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Italian terms suffixed with -issimo",
          "parents": [],
          "source": "w"
        }
      ],
      "form_of": [
        {
          "extra": "very full; full up",
          "word": "pieno"
        }
      ],
      "glosses": [
        "superlative degree of pieno (“very full; full up”)"
      ],
      "id": "en-pienissimo-it-adj-nN60c3Ct",
      "links": [
        [
          "pieno",
          "pieno#Italian"
        ],
        [
          "full",
          "full"
        ],
        [
          "full up",
          "full up"
        ]
      ],
      "tags": [
        "form-of",
        "superlative"
      ]
    }
  ],
  "word": "pienissimo"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "it",
        "2": "pieno",
        "3": "-issimo"
      },
      "expansion": "pieno + -issimo",
      "name": "af"
    }
  ],
  "etymology_text": "From pieno + -issimo.",
  "forms": [
    {
      "form": "pienissima",
      "tags": [
        "feminine"
      ]
    },
    {
      "form": "pienissimi",
      "tags": [
        "masculine",
        "plural"
      ]
    },
    {
      "form": "pienissime",
      "tags": [
        "feminine",
        "plural"
      ]
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        "Italian adjectives",
        "Italian entries with incorrect language header",
        "Italian lemmas",
        "Italian superlative adjectives",
        "Italian terms suffixed with -issimo"
      ],
      "form_of": [
        {
          "extra": "very full; full up",
          "word": "pieno"
        }
      ],
      "glosses": [
        "superlative degree of pieno (“very full; full up”)"
      ],
      "links": [
        [
          "pieno",
          "pieno#Italian"
        ],
        [
          "full",
          "full"
        ],
        [
          "full up",
          "full up"
        ]
      ],
      "tags": [
        "form-of",
        "superlative"
      ]
    }
  ],
  "word": "pienissimo"
}