"-immo" meaning in Italian

{
  "etymology_templates": [
    {
      "args": {
        "1": "it",
        "2": "la",
        "3": "-īvimus"
      },
      "expansion": "Latin -īvimus",
      "name": "der"
    },
    {
      "args": {
        "1": "la",
        "2": "finivimus"
      },
      "expansion": "Latin finivimus",
      "name": "cog"
    }
  ],
  "etymology_text": "From Latin -īvimus (via -īvmus).\nExample: Italian finimmo, from Latin finivimus.",
  "lang": "Italian",
  "lang_code": "it",
  "pos": "suffix",
  "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"
        }
      ],
      "glosses": [
        "used with a stem to form the first-person plural past historic of regular -ire verbs"
      ],
      "id": "en--immo-it-suffix-bGo8Nvo6",
      "links": [
        [
          "first-person",
          "first person#English"
        ],
        [
          "plural",
          "plural#English"
        ],
        [
          "past historic",
          "past historic#English"
        ],
        [
          "-ire",
          "-ire#Italian"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "-immo"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "it",
        "2": "la",
        "3": "-īvimus"
      },
      "expansion": "Latin -īvimus",
      "name": "der"
    },
    {
      "args": {
        "1": "la",
        "2": "finivimus"
      },
      "expansion": "Latin finivimus",
      "name": "cog"
    }
  ],
  "etymology_text": "From Latin -īvimus (via -īvmus).\nExample: Italian finimmo, from Latin finivimus.",
  "lang": "Italian",
  "lang_code": "it",
  "pos": "suffix",
  "senses": [
    {
      "categories": [
        "Italian entries with incorrect language header",
        "Italian non-lemma forms",
        "Italian suffix forms",
        "Italian terms derived from Latin",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "glosses": [
        "used with a stem to form the first-person plural past historic of regular -ire verbs"
      ],
      "links": [
        [
          "first-person",
          "first person#English"
        ],
        [
          "plural",
          "plural#English"
        ],
        [
          "past historic",
          "past historic#English"
        ],
        [
          "-ire",
          "-ire#Italian"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "-immo"
}

{
  "called_from": "form_descriptions/1698",
  "msg": "unrecognized head form: non-lemma form of verb-forming suffix",
  "path": [
    "-immo"
  ],
  "section": "Italian",
  "subsection": "suffix",
  "title": "-immo",
  "trace": ""
}