"mud run" meaning in English

{
  "forms": [
    {
      "form": "mud runs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "mud run (plural mud runs)",
      "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": "topical",
          "langcode": "en",
          "name": "Athletics",
          "orig": "en:Athletics",
          "parents": [
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "2014, Joe De Sena, Spartan Up!: A Take-No-Prisoners Guide to Overcoming Obstacles and Achieving Peak Performance in Life, page 141",
          "text": "I recently received a note from a young man named Austin who had encountered Spartan Race after trying a mud run put on by another promoter.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "An athletic event in which runners compete to navigate an obstacle course designed to include stretches of mud."
      ],
      "id": "en-mud_run-en-noun-EobP0bOa",
      "links": [
        [
          "obstacle course",
          "obstacle course"
        ],
        [
          "mud",
          "mud"
        ]
      ]
    }
  ],
  "word": "mud run"
}

{
  "forms": [
    {
      "form": "mud runs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "mud run (plural mud runs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms with quotations",
        "Quotation templates to be cleaned",
        "en:Athletics"
      ],
      "examples": [
        {
          "ref": "2014, Joe De Sena, Spartan Up!: A Take-No-Prisoners Guide to Overcoming Obstacles and Achieving Peak Performance in Life, page 141",
          "text": "I recently received a note from a young man named Austin who had encountered Spartan Race after trying a mud run put on by another promoter.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "An athletic event in which runners compete to navigate an obstacle course designed to include stretches of mud."
      ],
      "links": [
        [
          "obstacle course",
          "obstacle course"
        ],
        [
          "mud",
          "mud"
        ]
      ]
    }
  ],
  "word": "mud run"
}