"rearing bit" meaning in English

{
  "forms": [
    {
      "form": "rearing bits",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "rearing bit (plural rearing bits)",
      "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": "lifeform",
          "langcode": "en",
          "name": "Horse tack",
          "orig": "en:Horse tack",
          "parents": [
            "Animal riding",
            "Horses",
            "Tools",
            "Transport",
            "Equids",
            "Livestock",
            "Technology",
            "All topics",
            "Odd-toed ungulates",
            "Agriculture",
            "Animals",
            "Fundamental",
            "Mammals",
            "Applied sciences",
            "Lifeforms",
            "Vertebrates",
            "Sciences",
            "Life",
            "Chordates",
            "Nature"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1857, Harry Hieover, Precept and Practice",
          "text": "[if the horse] tosses up his head so violently or pertinaciously as to become unbearable , ride him a few times in a rearing bit",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A bit designed to prevent a horse from lifting the head when rearing."
      ],
      "id": "en-rearing_bit-en-noun-yskAXL86",
      "links": [
        [
          "bit",
          "bit"
        ],
        [
          "rear",
          "rear"
        ]
      ]
    }
  ],
  "word": "rearing bit"
}

{
  "forms": [
    {
      "form": "rearing bits",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "rearing bit (plural rearing bits)",
      "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",
        "en:Horse tack"
      ],
      "examples": [
        {
          "ref": "1857, Harry Hieover, Precept and Practice",
          "text": "[if the horse] tosses up his head so violently or pertinaciously as to become unbearable , ride him a few times in a rearing bit",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A bit designed to prevent a horse from lifting the head when rearing."
      ],
      "links": [
        [
          "bit",
          "bit"
        ],
        [
          "rear",
          "rear"
        ]
      ]
    }
  ],
  "word": "rearing bit"
}