oscillation vs palpitation

oscillation

noun
  • the act of oscillating or the state of being oscillated 

  • (of a function) defined for each point x in the domain of the function by inf diam(f(U))∣Uisaneighborhoodofx, and describes the difference (possibly ∞) between the limit superior and limit inferior of the function near that point. 

  • a single such cycle 

  • a regular periodic fluctuation in value about some mean 

palpitation

noun
  • An abnormal beating of the heart that may be perceived by the patient, a result of excitement, exertion, or illness. 

How often have the words oscillation and palpitation occurred in a corpus of books? (source: Google Ngram Viewer )