herd vs let in

herd

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

  • 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 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. 

let in

verb
  • To associate with. 

  • To let someone or something come in; to admit someone or something in. 

  • To divulge one's inner thoughts to (someone), making oneself emotionally vulnerable to them; to open up to (someone). 

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