herd vs mob

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. 

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. 

mob

noun
  • A group of animals such as horses or cattle. 

  • A mob cap. 

  • See also: Mob, Mafia (proper noun senses for specific ones) 

  • mobile phone 

  • See also: Mob (the masses) 

  • A large or disorderly group of people; especially one bent on riotous or destructive action. 

  • A group of kangaroos. 

  • A mafia: a group that engages in organized crime. 

  • A non-player character, especially one that exists to be fought or killed to further the progression of the story or game. 

  • A group of Aboriginal people associated with an extended family group, clan group or wider community group, from a particular place or country. 

  • A flock of emus. 

verb
  • To wrap up in, or cover with, a cowl. 

  • To crowd around (someone), sometimes with hostility. 

  • To crowd into or around a place. 

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