judder

Short definition from Wiktionary

Noun

1. 1
   A spasmodic shaking.
2. 2
   Jerky playback caused by converting between frame rates; telecine judder

Verb

1. 1
   To spasm or shake violently.
2. 2
   To move with a stop-start motion, as if experiencing a strong resistance or when decelerating brusquely.