"road apple" meaning in English

{
  "etymology_text": "Probably with reference to the supposed similarity to rotten apples.",
  "forms": [
    {
      "form": "road apples",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "road apple (plural road apples)",
      "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 topic categories using raw markup",
          "parents": [
            "Entries with topic 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"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Roads",
          "orig": "en:Roads",
          "parents": [
            "Road transport",
            "Transport",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1964, P. S. Martin, F. W. Sharrock, “Pollen Analysis of Prehistoric Human Feces: A New Approach to Ethnobotany”, in American Antiquity, volume 30, number 2, page 171",
          "text": "Samples 7–12 contained coarsely chewed plant material; several closely resembled the \"road apples\" of horse and burro.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Horse manure, especially when deposited on a road."
      ],
      "id": "en-road_apple-en-noun-Lc~rcK74",
      "links": [
        [
          "Horse",
          "horse"
        ],
        [
          "manure",
          "manure"
        ],
        [
          "deposit",
          "deposit"
        ]
      ],
      "raw_glosses": [
        "(slang, dated, often in the plural) Horse manure, especially when deposited on a road."
      ],
      "synonyms": [
        {
          "word": "street apple"
        }
      ],
      "tags": [
        "dated",
        "in-plural",
        "often",
        "slang"
      ],
      "translations": [
        {
          "code": "cs",
          "lang": "Czech",
          "sense": "road apple",
          "tags": [
            "feminine"
          ],
          "word": "koňská kobliha"
        },
        {
          "code": "de",
          "lang": "German",
          "sense": "road apple",
          "tags": [
            "masculine"
          ],
          "word": "Pferdeapfel"
        }
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-road apple.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/a/ab/En-au-road_apple.ogg/En-au-road_apple.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/a/ab/En-au-road_apple.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "road apple"
}

{
  "etymology_text": "Probably with reference to the supposed similarity to rotten apples.",
  "forms": [
    {
      "form": "road apples",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "road apple (plural road apples)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English dated terms",
        "English entries with incorrect language header",
        "English entries with topic categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English slang",
        "English terms with audio links",
        "English terms with non-redundant non-automated sortkeys",
        "English terms with quotations",
        "en:Roads"
      ],
      "examples": [
        {
          "ref": "1964, P. S. Martin, F. W. Sharrock, “Pollen Analysis of Prehistoric Human Feces: A New Approach to Ethnobotany”, in American Antiquity, volume 30, number 2, page 171",
          "text": "Samples 7–12 contained coarsely chewed plant material; several closely resembled the \"road apples\" of horse and burro.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "Horse manure, especially when deposited on a road."
      ],
      "links": [
        [
          "Horse",
          "horse"
        ],
        [
          "manure",
          "manure"
        ],
        [
          "deposit",
          "deposit"
        ]
      ],
      "raw_glosses": [
        "(slang, dated, often in the plural) Horse manure, especially when deposited on a road."
      ],
      "synonyms": [
        {
          "word": "street apple"
        }
      ],
      "tags": [
        "dated",
        "in-plural",
        "often",
        "slang"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-road apple.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/a/ab/En-au-road_apple.ogg/En-au-road_apple.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/a/ab/En-au-road_apple.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "translations": [
    {
      "code": "cs",
      "lang": "Czech",
      "sense": "road apple",
      "tags": [
        "feminine"
      ],
      "word": "koňská kobliha"
    },
    {
      "code": "de",
      "lang": "German",
      "sense": "road apple",
      "tags": [
        "masculine"
      ],
      "word": "Pferdeapfel"
    }
  ],
  "word": "road apple"
}