"figlio unico" meaning in Italian

{
  "forms": [
    {
      "form": "figli unici",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "figlia unica",
      "tags": [
        "feminine"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "f": "+"
      },
      "expansion": "figlio unico m (plural figli unici, feminine figlia unica)",
      "name": "it-noun"
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Italian entries with incorrect language header",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "langcode": "it",
          "name": "Male family members",
          "orig": "it:Male family members",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "english": "I'm an only child.",
          "text": "Sono figlio unico.",
          "translation": "I'm an only child.",
          "type": "example"
        }
      ],
      "glosses": [
        "male only child"
      ],
      "id": "en-figlio_unico-it-noun-NJlDHHul",
      "links": [
        [
          "only child",
          "only child"
        ]
      ],
      "qualifier": "family",
      "raw_glosses": [
        "(family) male only child"
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "word": "figlio unico"
}

{
  "forms": [
    {
      "form": "figli unici",
      "tags": [
        "plural"
      ]
    },
    {
      "form": "figlia unica",
      "tags": [
        "feminine"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "f": "+"
      },
      "expansion": "figlio unico m (plural figli unici, feminine figlia unica)",
      "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",
        "Italian terms with usage examples",
        "Pages with 1 entry",
        "Pages with entries",
        "it:Male family members"
      ],
      "examples": [
        {
          "english": "I'm an only child.",
          "text": "Sono figlio unico.",
          "translation": "I'm an only child.",
          "type": "example"
        }
      ],
      "glosses": [
        "male only child"
      ],
      "links": [
        [
          "only child",
          "only child"
        ]
      ],
      "qualifier": "family",
      "raw_glosses": [
        "(family) male only child"
      ],
      "tags": [
        "masculine"
      ]
    }
  ],
  "word": "figlio unico"
}