perturb vs put off

perturb

verb
  • To disturb; to bother or unsettle. 

  • To modify the motion of a body by exerting a gravitational force. 

  • To modify slightly, such as an equation or value. 

  • To slightly modify the motion of an object. 

put off

verb
  • To distract; to disturb the concentration of. 

  • To procrastinate. 

  • To emit; to give off (an odor, smoke, etc.). 

  • To cause to dislike; to discourage (from doing). 

  • To delay (a task, event, etc.). 

adj
  • daunted or fazed 

  • offended, repulsed 

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