pile up vs rid

pile up

verb
  • To collect or accumulate, as a backlog. 

  • To form a pile, stack, or heap. 

rid

verb
  • To free (something) from a hindrance or annoyance. 

adj
  • Released from an obligation, problem, etc. (usually followed by of). 

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