"épreuve de force" meaning in French

{
  "etymology_text": "Literally, “test of strength.”",
  "forms": [
    {
      "form": "épreuves de force",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "épreuve de force f (plural épreuves de force)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "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 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "Near-synonym: bras de fer"
        }
      ],
      "glosses": [
        "showdown, power struggle"
      ],
      "id": "en-épreuve_de_force-fr-noun-avB1QRbw",
      "links": [
        [
          "showdown",
          "showdown"
        ],
        [
          "power struggle",
          "power struggle"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/e.pʁœv də fɔʁs/"
    }
  ],
  "word": "épreuve de force"
}

{
  "etymology_text": "Literally, “test of strength.”",
  "forms": [
    {
      "form": "épreuves de force",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {
        "1": "f"
      },
      "expansion": "épreuve de force f (plural épreuves de force)",
      "name": "fr-noun"
    }
  ],
  "lang": "French",
  "lang_code": "fr",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "French countable nouns",
        "French entries with incorrect language header",
        "French feminine nouns",
        "French lemmas",
        "French multiword terms",
        "French nouns",
        "French nouns with red links in their headword lines",
        "French terms with IPA pronunciation",
        "Pages with 1 entry",
        "Pages with entries"
      ],
      "examples": [
        {
          "text": "Near-synonym: bras de fer"
        }
      ],
      "glosses": [
        "showdown, power struggle"
      ],
      "links": [
        [
          "showdown",
          "showdown"
        ],
        [
          "power struggle",
          "power struggle"
        ]
      ],
      "tags": [
        "feminine"
      ]
    }
  ],
  "sounds": [
    {
      "ipa": "/e.pʁœv də fɔʁs/"
    }
  ],
  "word": "épreuve de force"
}