"Prony brake" meaning in English

{
  "etymology_text": "Invented by Gaspard de Prony in 1821.",
  "forms": [
    {
      "form": "Prony brakes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Prony brake (plural Prony brakes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A device to measure the torque produced by an engine, essentially by wrapping a cord or belt around the output shaft and measuring the force transferred to the belt through friction."
      ],
      "id": "en-Prony_brake-en-noun-4Vjr1d2U",
      "links": [
        [
          "device",
          "device"
        ],
        [
          "measure",
          "measure"
        ],
        [
          "torque",
          "torque"
        ],
        [
          "engine",
          "engine"
        ],
        [
          "force",
          "force"
        ],
        [
          "friction",
          "friction"
        ]
      ]
    }
  ],
  "word": "Prony brake"
}

{
  "etymology_text": "Invented by Gaspard de Prony in 1821.",
  "forms": [
    {
      "form": "Prony brakes",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "Prony brake (plural Prony brakes)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English eponyms",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "A device to measure the torque produced by an engine, essentially by wrapping a cord or belt around the output shaft and measuring the force transferred to the belt through friction."
      ],
      "links": [
        [
          "device",
          "device"
        ],
        [
          "measure",
          "measure"
        ],
        [
          "torque",
          "torque"
        ],
        [
          "engine",
          "engine"
        ],
        [
          "force",
          "force"
        ],
        [
          "friction",
          "friction"
        ]
      ]
    }
  ],
  "word": "Prony brake"
}