foretoken vs portend

foretoken

verb
  • To betoken beforehand; prognosticate; foreshadow; give warning of; presage. 

noun
  • A prognostic; a premonitory sign; warning or presentiment. 

portend

verb
  • To serve as a warning or omen of. 

  • To signify; to denote. 

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