"a fortiori" meaning in French

{
  "forms": [
    {
      "form": "à fortiori",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "nolinkhead": "1"
      },
      "expansion": "a fortiori",
      "name": "fr-adv"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 5 entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "glosses": [
        "a fortiori (A form of argumentation that draws upon existing confidence in a proposition to argue in favor of a second proposition that is held to be implicit in, and even more certain than, the first.)"
      ],
      "id": "en-a_fortiori-fr-adv-UaIrw7Cz",
      "links": [
        [
          "a fortiori",
          "a fortiori#English"
        ]
      ],
      "synonyms": [
        {
          "word": "à plus forte raison"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/a fɔʁ.sjɔ.ʁi/"
    }
  ],
  "word": "a fortiori"
}

{
  "forms": [
    {
      "form": "à fortiori",
      "tags": [
        "alternative"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "nolinkhead": "1"
      },
      "expansion": "a fortiori",
      "name": "fr-adv"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adv",
  "senses": [
    {
      "categories": [
        "French adverbs",
        "French entries with incorrect language header",
        "French lemmas",
        "French multiword terms",
        "French terms with IPA pronunciation",
        "Pages with 5 entries",
        "Pages with entries"
      ],
      "glosses": [
        "a fortiori (A form of argumentation that draws upon existing confidence in a proposition to argue in favor of a second proposition that is held to be implicit in, and even more certain than, the first.)"
      ],
      "links": [
        [
          "a fortiori",
          "a fortiori#English"
        ]
      ],
      "synonyms": [
        {
          "word": "à plus forte raison"
        }
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/a fɔʁ.sjɔ.ʁi/"
    }
  ],
  "word": "a fortiori"
}