"della prima ora" meaning in Italien

{
  "categories": [
    {
      "kind": "other",
      "name": "Compositions en italien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Locutions adverbiales en italien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Italien",
      "orig": "italien",
      "parents": [],
      "source": "w"
    }
  ],
  "etymology_texts": [
    "Composé de della, prima et ora."
  ],
  "lang": "Italien",
  "lang_code": "it",
  "pos": "adv",
  "pos_title": "Locution adverbiale",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "Wiktionnaire:Exemples manquants en italien",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "De la première heure, depuis les débuts."
      ],
      "id": "fr-della_prima_ora-it-adv-zgYNRMoI"
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈdel.la ˈpri.ma ˈo.ra\\"
    }
  ],
  "tags": [
    "invariable"
  ],
  "word": "della prima ora"
}

{
  "categories": [
    "Compositions en italien",
    "Locutions adverbiales en italien",
    "italien"
  ],
  "etymology_texts": [
    "Composé de della, prima et ora."
  ],
  "lang": "Italien",
  "lang_code": "it",
  "pos": "adv",
  "pos_title": "Locution adverbiale",
  "senses": [
    {
      "categories": [
        "Wiktionnaire:Exemples manquants en italien"
      ],
      "glosses": [
        "De la première heure, depuis les débuts."
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "\\ˈdel.la ˈpri.ma ˈo.ra\\"
    }
  ],
  "tags": [
    "invariable"
  ],
  "word": "della prima ora"
}