"-ю-" meaning in Russian

{
  "forms": [
    {
      "form": "-ю́-",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "-jú-",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ru",
        "2": "interfix",
        "head": "-ю́-"
      },
      "expansion": "-ю́- • (-jú-)",
      "name": "head"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "interfix",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Russian interfixes",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "Used to form adjectives of the form \"N times removed\", referring to types of cousins. Originally the genitive dual ending of Old East Slavic дъвою (dŭvoju, “of two”)."
      ],
      "id": "en--ю--ru-interfix-LU9SNrCL",
      "links": [
        [
          "cousin",
          "cousin#English"
        ],
        [
          "Old East Slavic",
          "w:Old East Slavic language"
        ],
        [
          "дъвою",
          "дъва#Old East Slavic"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈʲu]"
    }
  ],
  "word": "-ю-"
}

{
  "forms": [
    {
      "form": "-ю́-",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "-jú-",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "ru",
        "2": "interfix",
        "head": "-ю́-"
      },
      "expansion": "-ю́- • (-jú-)",
      "name": "head"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "interfix",
  "senses": [
    {
      "categories": [
        "Russian 1-syllable words",
        "Russian entries with incorrect language header",
        "Russian interfixes",
        "Russian lemmas",
        "Russian terms with IPA pronunciation"
      ],
      "glosses": [
        "Used to form adjectives of the form \"N times removed\", referring to types of cousins. Originally the genitive dual ending of Old East Slavic дъвою (dŭvoju, “of two”)."
      ],
      "links": [
        [
          "cousin",
          "cousin#English"
        ],
        [
          "Old East Slavic",
          "w:Old East Slavic language"
        ],
        [
          "дъвою",
          "дъва#Old East Slavic"
        ]
      ],
      "tags": [
        "morpheme"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[ˈʲu]"
    }
  ],
  "word": "-ю-"
}