"sans précédent" meaning in French

{
  "head_templates": [
    {
      "args": {
        "inv": "1"
      },
      "expansion": "sans précédent (invariable)",
      "name": "fr-adj"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adj",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "French entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "unprecedented"
      ],
      "id": "en-sans_précédent-fr-adj-G65CDZFr",
      "links": [
        [
          "unprecedented",
          "unprecedented"
        ]
      ],
      "related": [
        {
          "word": "sans pareil"
        }
      ],
      "tags": [
        "invariable"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/sɑ̃ pʁe.se.dɑ̃/"
    }
  ],
  "word": "sans précédent"
}

{
  "head_templates": [
    {
      "args": {
        "inv": "1"
      },
      "expansion": "sans précédent (invariable)",
      "name": "fr-adj"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "adj",
  "related": [
    {
      "word": "sans pareil"
    }
  ],
  "senses": [
    {
      "categories": [
        "French adjectives",
        "French entries with incorrect language header",
        "French lemmas",
        "French multiword terms",
        "French terms with IPA pronunciation"
      ],
      "glosses": [
        "unprecedented"
      ],
      "links": [
        [
          "unprecedented",
          "unprecedented"
        ]
      ],
      "tags": [
        "invariable"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/sɑ̃ pʁe.se.dɑ̃/"
    }
  ],
  "word": "sans précédent"
}