knuckleball
noun
Definitions
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.
Example: Boston Red Sox pitcher Tim Wakefield is best known for his use of the knuckleball.
An event that is hard to predict.
Example: Our vendor keeps throwing us knuckleballs.
verb
Definitions
To pitch knuckleballs.