"knuckler" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "knuckle",
        "3": "er",
        "id2": "relational"
      },
      "expansion": "knuckle + -er",
      "name": "suffix"
    }
  ],
  "etymology_text": "knuckle + -er",
  "forms": [
    {
      "form": "knucklers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "knuckler (plural knucklers)",
      "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 terms suffixed with -er (relational)",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Baseball",
          "orig": "en:Baseball",
          "parents": [
            "Ball games",
            "Sports",
            "Human activity",
            "Human behaviour",
            "Human",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "ref": "1952, Bernard Malamud, chapter 2, in The Natural",
          "text": "Fowler flung a stiff-wrist knuckler that hung in the air without spin before it took a sudden dip, but Roy scooped it up with the stick and lifted it twenty rows up into the center field stands.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A knuckleball."
      ],
      "id": "en-knuckler-en-noun-QDQzryMe",
      "links": [
        [
          "baseball",
          "baseball"
        ],
        [
          "knuckleball",
          "knuckleball"
        ]
      ],
      "raw_glosses": [
        "(baseball slang) A knuckleball."
      ],
      "related": [
        {
          "word": "curveball"
        },
        {
          "word": "slider"
        },
        {
          "word": "fastball"
        },
        {
          "word": "cut fastball"
        },
        {
          "word": "two-seam fastball"
        },
        {
          "word": "split-finger fastball"
        },
        {
          "word": "sinker"
        },
        {
          "word": "screwball"
        }
      ],
      "tags": [
        "slang"
      ],
      "topics": [
        "ball-games",
        "baseball",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-knuckler.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/b/bf/En-au-knuckler.ogg/En-au-knuckler.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/b/bf/En-au-knuckler.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "knuckler"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "knuckle",
        "3": "er",
        "id2": "relational"
      },
      "expansion": "knuckle + -er",
      "name": "suffix"
    }
  ],
  "etymology_text": "knuckle + -er",
  "forms": [
    {
      "form": "knucklers",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "knuckler (plural knucklers)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "word": "curveball"
    },
    {
      "word": "slider"
    },
    {
      "word": "fastball"
    },
    {
      "word": "cut fastball"
    },
    {
      "word": "two-seam fastball"
    },
    {
      "word": "split-finger fastball"
    },
    {
      "word": "sinker"
    },
    {
      "word": "screwball"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English slang",
        "English terms suffixed with -er (relational)",
        "English terms with audio links",
        "English terms with quotations",
        "Quotation templates to be cleaned",
        "en:Baseball"
      ],
      "examples": [
        {
          "ref": "1952, Bernard Malamud, chapter 2, in The Natural",
          "text": "Fowler flung a stiff-wrist knuckler that hung in the air without spin before it took a sudden dip, but Roy scooped it up with the stick and lifted it twenty rows up into the center field stands.",
          "type": "quotation"
        }
      ],
      "glosses": [
        "A knuckleball."
      ],
      "links": [
        [
          "baseball",
          "baseball"
        ],
        [
          "knuckleball",
          "knuckleball"
        ]
      ],
      "raw_glosses": [
        "(baseball slang) A knuckleball."
      ],
      "tags": [
        "slang"
      ],
      "topics": [
        "ball-games",
        "baseball",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "sounds": [
    {
      "audio": "En-au-knuckler.ogg",
      "mp3_url": "https://upload.wikimedia.org/wikipedia/commons/transcoded/b/bf/En-au-knuckler.ogg/En-au-knuckler.ogg.mp3",
      "ogg_url": "https://upload.wikimedia.org/wikipedia/commons/b/bf/En-au-knuckler.ogg",
      "tags": [
        "Australia"
      ],
      "text": "Audio (AU)"
    }
  ],
  "word": "knuckler"
}