"-со-" meaning in Moksha

{
  "etymology_templates": [
    {
      "args": {
        "1": "mdf",
        "2": "-са",
        "3": "-о-"
      },
      "expansion": "-са (-sa) + -о- (-o-)",
      "name": "affix"
    }
  ],
  "etymology_text": "From -са (-sa) + -о- (-o-).",
  "forms": [
    {
      "form": "-so-",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "mdf",
        "2": "interfix"
      },
      "expansion": "-со- • (-so-)",
      "name": "head"
    }
  ],
  "lang": "Moksha",
  "lang_code": "mdf",
  "pos": "interfix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Moksha entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Moksha interfixes",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Moksha terms interfixed with -о-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Moksha terms suffixed with -са",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "O. Je. Poljakov (1993) Russko-mokšanskij razgovornik [Russian-Moksha phrasebook], Saransk: Mordovskoje knižnoje izdatelʹstvo, →ISBN\nкяльса — кяльсот\nkäľ sa — käľ so t\nin tongue — in your tongue",
          "type": "example"
        }
      ],
      "glosses": [
        "interfix variant of the inessive suffix"
      ],
      "id": "en--со--mdf-interfix-EGgnp22n",
      "links": [
        [
          "inessive",
          "inessive#English"
        ]
      ],
      "synonyms": [
        {
          "roman": "-sa",
          "word": "-са"
        }
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "word": "-со-"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "mdf",
        "2": "-са",
        "3": "-о-"
      },
      "expansion": "-са (-sa) + -о- (-o-)",
      "name": "affix"
    }
  ],
  "etymology_text": "From -са (-sa) + -о- (-o-).",
  "forms": [
    {
      "form": "-so-",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "mdf",
        "2": "interfix"
      },
      "expansion": "-со- • (-so-)",
      "name": "head"
    }
  ],
  "lang": "Moksha",
  "lang_code": "mdf",
  "pos": "interfix",
  "senses": [
    {
      "categories": [
        "Moksha entries with incorrect language header",
        "Moksha interfixes",
        "Moksha lemmas",
        "Moksha terms interfixed with -о-",
        "Moksha terms suffixed with -са",
        "Moksha terms with usage examples",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "O. Je. Poljakov (1993) Russko-mokšanskij razgovornik [Russian-Moksha phrasebook], Saransk: Mordovskoje knižnoje izdatelʹstvo, →ISBN\nкяльса — кяльсот\nkäľ sa — käľ so t\nin tongue — in your tongue",
          "type": "example"
        }
      ],
      "glosses": [
        "interfix variant of the inessive suffix"
      ],
      "links": [
        [
          "inessive",
          "inessive#English"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "synonyms": [
    {
      "roman": "-sa",
      "word": "-са"
    }
  ],
  "word": "-со-"
}