dispersal vs horde

dispersal

noun
  • The act or result of dispersing or scattering; dispersion. 

  • A dispersal prison. 

horde

noun
  • A wandering troop or gang; especially, a clan or tribe of a nomadic people (originally Tatars) migrating from place to place for the sake of pasturage, plunder, etc.; a predatory multitude. 

  • A large number of people or things. 

verb
  • to travel en masse, to flock 

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