dispel vs round up

dispel

verb
  • To drive away or cause to vanish by scattering. 

  • To remove (fears, doubts, objections etc.) by proving them unjustified. 

noun
  • An act or instance of dispelling. 

round up

verb
  • To gather (cattle) together by riding around them. 

  • To round (a number) to the smallest integer that is not less than it, or to some other greater value, especially a whole number of hundreds, thousands, etc. 

  • To arrest or detain a group of people without individualized suspicion or cause, often as a form of targeted persecution. 

  • To collect or gather (something) together. 

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