"nucleo interno" meaning in Italian

{
  "forms": [
    {
      "form": "nuclei interni",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "nucleo interno m (plural nuclei interni)",
      "name": "it-noun"
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Italian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "it",
          "name": "Geology",
          "orig": "it:Geology",
          "parents": [
            "Earth sciences",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "inner core"
      ],
      "id": "en-nucleo_interno-it-noun-Gy5Dp7ek",
      "links": [
        [
          "geology",
          "geology"
        ],
        [
          "inner core",
          "inner core"
        ]
      ],
      "raw_glosses": [
        "(geology) inner core"
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "geography",
        "geology",
        "natural-sciences"
      ]
    }
  ],
  "word": "nucleo interno"
}

{
  "forms": [
    {
      "form": "nuclei interni",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m"
      },
      "expansion": "nucleo interno m (plural nuclei interni)",
      "name": "it-noun"
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "Italian countable nouns",
        "Italian entries with incorrect language header",
        "Italian lemmas",
        "Italian masculine nouns",
        "Italian multiword terms",
        "Italian nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "it:Geology"
      ],
      "glosses": [
        "inner core"
      ],
      "links": [
        [
          "geology",
          "geology"
        ],
        [
          "inner core",
          "inner core"
        ]
      ],
      "raw_glosses": [
        "(geology) inner core"
      ],
      "tags": [
        "masculine"
      ],
      "topics": [
        "geography",
        "geology",
        "natural-sciences"
      ]
    }
  ],
  "word": "nucleo interno"
}