tic vs tremor

tic

noun
  • A sudden, nonrhythmic motor movement or vocalization. 

  • ticket 

  • Something that is done or produced habitually or characteristically. 

verb
  • To exhibit a tic; to undergo a sudden, semi-voluntary muscle movement. 

tremor

noun
  • A rhythmic, uncontrollable shaking of all or part of the body due to partial muscle contractions. 

  • An earthquake. 

  • A shake, quiver, or vibration. 

verb
  • To shake or quiver excessively and rapidly or involuntarily; to tremble. 

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