"unue" meaning in Esperanto

{
  "etymology_templates": [
    {
      "args": {
        "1": "eo",
        "2": "unu",
        "3": "-e",
        "pos2": "adverbial suffix",
        "t1": "one"
      },
      "expansion": "unu (“one”) + -e (adverbial suffix)",
      "name": "suf"
    }
  ],
  "etymology_text": "From unu (“one”) + -e (adverbial suffix).",
  "head_templates": [
    {
      "args": {},
      "expansion": "unue",
      "name": "eo-head"
    }
  ],
  "hyphenation": [
    "u‧nu‧e"
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Esperanto entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Esperanto terms suffixed with -e",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "firstly; at first"
      ],
      "id": "en-unue-eo-adv-x8ySZj5G",
      "links": [
        [
          "firstly",
          "firstly"
        ],
        [
          "at first",
          "at first"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[uˈnue]"
    },
    {
      "rhymes": "-ue"
    }
  ],
  "word": "unue"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "eo",
        "2": "unu",
        "3": "-e",
        "pos2": "adverbial suffix",
        "t1": "one"
      },
      "expansion": "unu (“one”) + -e (adverbial suffix)",
      "name": "suf"
    }
  ],
  "etymology_text": "From unu (“one”) + -e (adverbial suffix).",
  "head_templates": [
    {
      "args": {},
      "expansion": "unue",
      "name": "eo-head"
    }
  ],
  "hyphenation": [
    "u‧nu‧e"
  ],
  "lang": "Esperanto",
  "lang_code": "eo",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "Esperanto adverbs",
        "Esperanto entries with incorrect language header",
        "Esperanto lemmas",
        "Esperanto terms suffixed with -e",
        "Esperanto terms with IPA pronunciation",
        "Esperanto terms with audio pronunciation",
        "Pages with 1 entry",
        "Pages with entries",
        "Rhymes:Esperanto/ue"
      ],
      "glosses": [
        "firstly; at first"
      ],
      "links": [
        [
          "firstly",
          "firstly"
        ],
        [
          "at first",
          "at first"
        ]
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "[uˈnue]"
    },
    {
      "rhymes": "-ue"
    }
  ],
  "word": "unue"
}