noun • /səˈkɑːd/ • 1) a sudden jerking movement (rare). 2) a rapid jerky movement of the eye (voluntary or involuntary) from one focus to another. 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 (music).
From French saccade, “a jerking movement”, derived from saccader, “to jerk, jolt”.