preserve vs rid

preserve

verb
  • To protect; to keep from harm or injury. 

  • To save from decay by the use of some preservative substance, such as sugar or salt; to season and prepare (fruits, meat, etc.) for storage. 

  • To maintain throughout; to keep intact. 

noun
  • An activity with restricted access. 

  • A sweet spread made of any of a variety of fruits. 

  • A reservation, a nature preserve. 

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 preserve and rid occurred in a corpus of books? (source: Google Ngram Viewer )