relent vs shut down

relent

verb
  • To slacken; to abate. 

  • To give in or be swayed; to become less hard, harsh, or cruel; to show clemency. 

noun
  • Stay; stop; delay. 

shut down

verb
  • To close, terminate, or end. 

  • To pass (another vehicle), especially quickly. 

  • To turn off or stop. 

  • To emotionally withdraw into oneself as a defense mechanism; to block out external stressors. 

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