palpitation
1. [ noun ] (medicine) a rapid and irregular heart beat
Related terms: symptom palpitate
2. [ noun ] a shaky motion
Synonyms: trembling shakiness tremor quiver quivering vibration shaking
Examples:

"the shaking of his fingers as he lit his pipe"

Related terms: motion tremolo tremor tremble quiver tremble
Similar spelling:   palpitating
  palpitate
  palpitant
  palpation