relent vs time lag

relent

noun
  • Stay; stop; delay. 

verb
  • To slacken; to abate. 

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

time lag

noun
  • A period of time between one event and another; a delay. 

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