jerking
n. C / U B2 Upper Intermediate US //ˈdʒɝkɪŋ// UK //dʒˈɜːkɪŋ// jerk·ing
n. a sudden, quick movement that is not smooth. You might feel this if a car stops very fast or if your muscles twitch.
n. a short, sudden, and spasmodic movement. Often refers to involuntary physical motions or the abrupt physical motion of a vehicle or machine.
The sudden jerking of the train made me spill my coffee.
The doctor noticed a slight jerking in the patient's leg during the reflex test.
The old engine started with a violent jerking that shook the entire chassis before finally settling into a rhythmic, if noisy, idle.