"four-seam fastball" meaning in English

{
  "forms": [
    {
      "form": "four-seam fastballs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "four-seam fastball (plural four-seam fastballs)",
      "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": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "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"
        }
      ],
      "glosses": [
        "A backspin pitch thrown with a ball gripped in the direction to cause four of the seams of the ball to cross the flight path and released with roughly equal pressure by the index and middle fingers"
      ],
      "id": "en-four-seam_fastball-en-noun-UbFrhD9s",
      "links": [
        [
          "baseball",
          "baseball"
        ],
        [
          "pitch",
          "pitch"
        ]
      ],
      "raw_glosses": [
        "(baseball) A backspin pitch thrown with a ball gripped in the direction to cause four of the seams of the ball to cross the flight path and released with roughly equal pressure by the index and middle fingers"
      ],
      "related": [
        {
          "word": "curveball"
        },
        {
          "word": "slider"
        },
        {
          "word": "fastball"
        },
        {
          "word": "cut fastball"
        },
        {
          "word": "two-seam fastball"
        },
        {
          "word": "split-finger fastball"
        },
        {
          "word": "sinker"
        },
        {
          "word": "screwball"
        },
        {
          "word": "knuckleball"
        }
      ],
      "topics": [
        "ball-games",
        "baseball",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "word": "four-seam fastball"
}

{
  "forms": [
    {
      "form": "four-seam fastballs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "four-seam fastball (plural four-seam fastballs)",
      "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"
    },
    {
      "word": "knuckleball"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Baseball"
      ],
      "glosses": [
        "A backspin pitch thrown with a ball gripped in the direction to cause four of the seams of the ball to cross the flight path and released with roughly equal pressure by the index and middle fingers"
      ],
      "links": [
        [
          "baseball",
          "baseball"
        ],
        [
          "pitch",
          "pitch"
        ]
      ],
      "raw_glosses": [
        "(baseball) A backspin pitch thrown with a ball gripped in the direction to cause four of the seams of the ball to cross the flight path and released with roughly equal pressure by the index and middle fingers"
      ],
      "topics": [
        "ball-games",
        "baseball",
        "games",
        "hobbies",
        "lifestyle",
        "sports"
      ]
    }
  ],
  "word": "four-seam fastball"
}