knuckleball

noun

1. A pitch thrown with the ball gripped on the fingertips and released with no rotation, which travels over an unpredictable path to the plate due to micro-turbulence in the air.

   “Even the pitcher doesn't know where his knuckleball is going.”

   “Boston Red Sox pitcher Tim Wakefield is best known for his use of the knuckleball.”

2. A type of delivery where a fast bowler holds the ball on the knuckles of the index and middle fingers.
3. (figuratively, informal)An event that is hard to predict.

   “Our vendor keeps throwing us knuckleballs.”

verb

1. (intransitive)To pitch knuckleballs.

   “Varitek did not start so Kevin Cash could catch the knuckleballing starter Tim Wakefield.”