centrifugal vs erratic

centrifugal

adj
  • Tending, or causing, to recede from the center. 

  • Expanding first at the summit, and later at the base, as a flower cluster. 

  • Having the radicle turned toward the sides of the fruit, as some embryos. 

noun
  • A rotating machine used to separate massecuite into sugar crystals and molasses. 

erratic

adj
  • Unsteady, random; prone to unexpected changes; not consistent. 

  • Deviating from normal opinions or actions; eccentric; odd. 

noun
  • A rock moved from one location to another, usually by a glacier. 

  • Anything that has erratic characteristics. 

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