herd vs troop

herd

verb
  • To move or drive a herd. 

  • To manage, care for or guard a herd 

  • To act as a herdsman or a shepherd. 

  • To unite or associate in 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. 

troop

verb
  • To move in numbers; to come or gather in crowds or troops. 

  • To march on; to go forward in haste. 

  • To move or march as if in a crowd. 

noun
  • Mushrooms that are in a close group but not close enough to be called a cluster. 

  • A group of meerkat families living together. 

  • A collection of people; a number; a multitude (in general). 

  • A company of actors; a troupe. 

  • A chapter of a national girl or boy scouts organization, consisting of one or more patrols of 6 to 8 youngsters each. 

  • A particular roll of the drum; a quick march. 

  • A group of baboons. 

  • A group of soldiers; military forces. 

  • A detachment of soldiers or police, especially horse artillery, armour, or state troopers. 

  • A small unit of cavalry or armour commanded by a captain, corresponding to a platoon or company of infantry. 

  • An individual soldier or member of a military force. 

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