Noun

1. a sudden jerking movement
2. a rapid jerky movement of the eye (voluntary or involuntary) from one focus to another
   • 1993, Will Self, My Idea of Fun,

     He added the bill with a single saccade of his pulsing eyes.

3. the act of checking a horse quickly with a single strong pull of the reins
4. the sounding of two violin strings together by using a sudden strong pressure of the bow