Definition of knuckleball in English:

knuckleball

noun

Baseball
  • A slow pitch which moves erratically, made by releasing the ball from the knuckles of the first joints of the index and middle finger.

    • ‘You'll learn the rules of offense and defense, and all about fastballs, curveballs, knuckleballs and screwballs.’
    • ‘He had pitched in high school and occasionally had thrown a knuckleball.’
    • ‘Wilhelm and Niekro are the only two pitchers in the Hall of Fame who relied primarily on the knuckleball throughout their careers.’
    • ‘Eddie Cicotte is thought to be the first major league pitcher to specialize in throwing the knuckleball.’
    • ‘Sauveur throws a fastball, knuckleball, curveball and cutter, and he changes speeds with all of them.’

Pronunciation:

knuckleball

/ˈnʌklbɔːl/