"Sig." meaning in Italian

{
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "#"
      },
      "expansion": "Sig. m (invariable)",
      "name": "it-noun"
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Mr",
          "word": "signor(e)"
        }
      ],
      "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"
        }
      ],
      "coordinate_terms": [
        {
          "english": "Ms./Mrs.",
          "translation": "Ms./Mrs.",
          "word": "Sig.ra"
        },
        {
          "english": "Dr.",
          "translation": "Dr.",
          "word": "Dott."
        }
      ],
      "glosses": [
        "abbreviation of signor(e): Mr."
      ],
      "id": "en-Sig.-it-noun-DRcNECGj",
      "links": [
        [
          "signor(e)",
          "signore#Italian"
        ],
        [
          "Mr.",
          "Mr."
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "invariable",
        "masculine"
      ]
    }
  ],
  "word": "Sig."
}

{
  "coordinate_terms": [
    {
      "english": "Ms./Mrs.",
      "translation": "Ms./Mrs.",
      "word": "Sig.ra"
    },
    {
      "english": "Dr.",
      "translation": "Dr.",
      "word": "Dott."
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "m",
        "2": "#"
      },
      "expansion": "Sig. m (invariable)",
      "name": "it-noun"
    }
  ],
  "lang": "Italian",
  "lang_code": "it",
  "pos": "noun",
  "senses": [
    {
      "alt_of": [
        {
          "extra": "Mr",
          "word": "signor(e)"
        }
      ],
      "categories": [
        "Italian abbreviations",
        "Italian countable nouns",
        "Italian entries with incorrect language header",
        "Italian indeclinable nouns",
        "Italian lemmas",
        "Italian masculine nouns",
        "Italian nouns",
        "Italian terms spelled with .",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "abbreviation of signor(e): Mr."
      ],
      "links": [
        [
          "signor(e)",
          "signore#Italian"
        ],
        [
          "Mr.",
          "Mr."
        ]
      ],
      "tags": [
        "abbreviation",
        "alt-of",
        "invariable",
        "masculine"
      ]
    }
  ],
  "word": "Sig."
}

{
  "called_from": "form_descriptions/2278",
  "msg": "suspicious alt_of/form_of with '(': signor(e)",
  "path": [
    "Sig."
  ],
  "section": "Italian",
  "subsection": "noun",
  "title": "Sig.",
  "trace": ""
}