"во-первых" meaning in Russian

{
  "forms": [
    {
      "form": "во-пе́рвых",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "vo-pérvyx",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "во-пе́рвых"
      },
      "expansion": "во-пе́рвых • (vo-pérvyx)",
      "name": "ru-adv"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Russian entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "ru",
          "name": "One",
          "orig": "ru:One",
          "parents": [
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "english": "\"I came here to warn you,\" he said. \"In the first place, don't lend me any money, for I shall certainly ask you to.\"",
          "ref": "1869, Фёдор Достоевский, “Глава VIII”, in Идиот (роман); English translation from Eva Martin, transl., The Idiot, 1913",
          "text": "— Я пришёл вас предупредить: во-первых, мне денег взаймы не давать, потому что я непременно буду просить.\n— Ja prišól vas predupreditʹ: vo-pervyx, mne deneg vzajmy ne davatʹ, potomu što ja nepremenno budu prositʹ.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "first, first of all, for one thing, firstly"
      ],
      "id": "en-во-первых-ru-adv-MPg~DiV6",
      "links": [
        [
          "first",
          "first"
        ],
        [
          "first of all",
          "first of all"
        ],
        [
          "for one thing",
          "for one thing"
        ],
        [
          "firstly",
          "firstly"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[vɐ‿ˈpʲervɨx]"
    },
    {
      "audio": "Ru-во-первых.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/2/23/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/2/23/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg",
      "text": "Audio"
    }
  ],
  "word": "во-первых"
}

{
  "forms": [
    {
      "form": "во-пе́рвых",
      "tags": [
        "canonical"
      ]
    },
    {
      "form": "vo-pérvyx",
      "tags": [
        "romanization"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "во-пе́рвых"
      },
      "expansion": "во-пе́рвых • (vo-pérvyx)",
      "name": "ru-adv"
    }
  ],
  "lang": "Russian",
  "lang_code": "ru",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "Russian adverbs",
        "Russian entries with incorrect language header",
        "Russian lemmas",
        "Russian multiword terms",
        "Russian terms with IPA pronunciation",
        "Russian terms with audio links",
        "Russian terms with quotations",
        "ru:One"
      ],
      "examples": [
        {
          "english": "\"I came here to warn you,\" he said. \"In the first place, don't lend me any money, for I shall certainly ask you to.\"",
          "ref": "1869, Фёдор Достоевский, “Глава VIII”, in Идиот (роман); English translation from Eva Martin, transl., The Idiot, 1913",
          "text": "— Я пришёл вас предупредить: во-первых, мне денег взаймы не давать, потому что я непременно буду просить.\n— Ja prišól vas predupreditʹ: vo-pervyx, mne deneg vzajmy ne davatʹ, potomu što ja nepremenno budu prositʹ.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "first, first of all, for one thing, firstly"
      ],
      "links": [
        [
          "first",
          "first"
        ],
        [
          "first of all",
          "first of all"
        ],
        [
          "for one thing",
          "for one thing"
        ],
        [
          "firstly",
          "firstly"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[vɐ‿ˈpʲervɨx]"
    },
    {
      "audio": "Ru-во-первых.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/2/23/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/2/23/Ru-%D0%B2%D0%BE-%D0%BF%D0%B5%D1%80%D0%B2%D1%8B%D1%85.ogg",
      "text": "Audio"
    }
  ],
  "word": "во-первых"
}