retard vs ride herd on

retard

noun
  • Retardation; delay. 

  • A slowing down of the tempo; a ritardando. 

  • A person or being who is extremely stupid or slow to learn. 

verb
  • To put off; to postpone. 

  • To decelerate; to slow down. 

  • To keep delaying; to continue to hinder; to prevent from progressing. 

ride herd on

verb
  • As the new editor, his job is to ride herd on the staff and check on the tone of the articles. 

  • To supervise a group of people and their work. 

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