herd vs middle class

herd

verb
  • To manage, care for or guard a herd 

  • To act as a herdsman or a shepherd. 

  • To unite or associate in a herd 

  • To move or drive a herd. 

  • To associate; to ally oneself with, or place oneself among, a group or company. 

  • To unite or associate in a herd; to feed or run together, or in company. 

  • To form or put into a herd. 

noun
  • A number of domestic animals assembled together under the watch or ownership of a keeper. 

  • Any collection of animals gathered or travelling in a company. 

  • A crowd, a mass of people or things; a rabble. 

middle class

noun
  • A social and economic class lying above the working class and below the upper class. 

  • The groups in society composed of professionals, semi-professionals, and lower to middle managerial level workers. 

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