petition vs precation

petition

noun
  • A prayer; a supplication; an entreaty. 

  • A compilation of signatures built in order to exert moral authority in support of a specific cause. 

  • A formal written request for judicial action. 

  • A formal, written request made to an official person or organized body, often containing many signatures. 

verb
  • To make a request to, commonly in written form. 

precation

noun
  • A prayer or act of praying; an earnest request. 

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